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A screw is a type of fastener, sometimes similar to a bolt (see Differentiation between bolt and screw below), typically made of metal, and characterized by a helical ridge, known as a male thread (external thread) or just thread.
A screw is an inclined plane wrapped around a nail. Some screw threads are designed to mate with a complementary thread, known as a female thread (internal thread), often in the form of a nut or an object that has the internal thread formed into it. Other screw threads are designed to cut a helical groove in a softer material as the screw is inserted. The most common uses of screws are to hold objects together and to position objects.
A screw will usually have a head on one end that contains a specially formed shape that allows it to be turned, or driven, with a tool. Common tools for driving screws include screwdrivers and wrenches. The head is usually larger than the body of the screw, which keeps the screw from being driven deeper than the length of the screw and to provide a bearing surface. There are exceptions; for instance, carriage bolts have a domed head that is not designed to be driven; set screws often have a head smaller than the outer diameter of the screw; J-bolts have a J-shaped head which is not designed to be driven, but rather is usually sunk into concrete allowing it to be used as an anchor bolt. The cylindrical portion of the screw from the underside of the head to the tip is known as the shank; it may be fully threaded or partially threaded.[1] The distance between each thread is called the "pitch".
The majority of screws are tightened by clockwise rotation, which is termed a right-hand thread; a common mnemonic device for remembering this when working with screws or bolts is "righty-tighty, lefty-loosey." Another rule is this: curl the fingers of your right hand around the screw with your thumb pointing is the direction you want the screw to go. If the screw is right-handed (most screws are) and you turn the screw in the direction of your fingers the screw will move in the direction of your thumb. Screws with left-hand threads are used in exceptional cases. For example, when the screw will be subject to counterclockwise torque (which would work to undo a right-hand thread), a left-hand-threaded screw would be an appropriate choice. The right side pedal of a bicycle has a left-hand thread.
More generally, screw may mean any helical device, such as a clamp, a micrometer, a ship's propeller or an Archimedes' screw water pump.
There is no universally accepted distinction between a screw and a bolt. A simple distinction that is often true, although not always, is that a bolt passes through a substrate and takes a nut on the other side, whereas a screw takes no nut because it threads directly into the substrate (a screw screws into something, a bolt bolts several things together). So, as a general rule, when buying a packet of "screws" you would not expect nuts to be included, but bolts are often sold with matching nuts. Part of the confusion over this is likely due to regional or dialectical differences. Machinery's Handbook describes the distinction as follows:
A bolt is an externally threaded fastener designed for insertion through holes in assembled parts, and is normally intended to be tightened or released by torquing a nut. A screw is an externally threaded fastener capable of being inserted into holes in assembled parts, of mating with a preformed internal thread or forming its own thread, and of being tightened or released by torquing the head. An externally threaded fastener which is prevented from being turned during assembly and which can be tightened or released only by torquing a nut is a bolt. (Example: round head bolts, track bolts, plow bolts.) An externally threaded fastener that has thread form which prohibits assembly with a nut having a straight thread of multiple pitch length is a screw. (Example: wood screws, tapping screws.)[2]
This distinction is consistent with ASME B18.2.1 and some dictionary definitions for screw[3][4] and bolt.[5][6][7]
The issue of what is a screw and what is a bolt is not completely resolved with Machinery's Handbook distinction, however, because of confounding terms, the ambiguous nature of some parts of the distinction, and usage variations.[8][not in citation given] Some of these issues are discussed below:
ASME standards specify a variety of "Machine Screws"[9] in diameters ranging up to 0.75 in (19.05 mm). These fasteners are often used with nuts but also often driven into tapped holes (without nuts). They might be considered a screw or a bolt based on the Machinery's Handbook distinction. In practice, they tend to be mostly available in smaller sizes and the smaller sizes are referred to as screws or less ambiguously as machine screws, although some kinds of machine screw can be referred to as stove bolts.
ASME standard B18.2.1-1996 specifies Hex Cap Screws whose size range is 0.25–3 in (6.35–76.20 mm) in diameter. These fasteners are very similar to hex bolts. They differ mostly in that they are manufactured to tighter tolerances than the corresponding bolts. Machinery's Handbook refers parenthetically to these fasteners as "Finished Hex Bolts".[10] Reasonably, these fasteners might be referred to as bolts, but based on the US government document Distinguishing Bolts from Screws, the US government might classify them as screws because of the tighter tolerance.[11] In 1991 responding to an influx of counterfeit fasteners Congress passed PL 101-592[12] "Fastener Quality Act" This resulted in the rewriting of specifications by the ASME B18 committee. B18.2.1[13] was re-written and as a result they eliminated the "Finished Hex Bolts" and renamed them the "Hex Cap Screw"—a term that had existed in common usage long before, but was now also being codified as an official name for the ASME B18 standard.
These terms refer to fasteners that are designed to be threaded into a tapped hole that is in part of the assembly and so based on the Machinery's Handbook distinction they would be screws. Here common terms are at variance with Machinery's Handbook distinction.[14][15]
Lag screws (US) or coach screws (UK, Australia, and New Zealand) (also referred to as lag bolts or coach bolts, although this is a misnomer) are large wood screws. Square-headed and hex-headed lag screws are covered by ASME B18.2.1 standards, and the head is typically an external hex. A typical lag screw can range in diameter from 1⁄4 in (6.35 mm) to 1 1⁄4 in (31.75 mm), and lengths from 1⁄4 to 6 in (6.35 to 152.40 mm) or longer, with the coarse threads of a wood-screw or sheet-metal-screw threadform (but larger).
The materials are usually carbon steel substrate with a coating of zinc galvanization (for corrosion resistance). The zinc coating may be bright (electroplated), yellow (electroplated), or dull gray hot-dip galvanized. Lag screws are used to lag together lumber framing, to lag machinery feet to wood floors, and for other heavy carpentry applications. The adjective lag came from an early principal use of such fasteners: the fastening of lags such as barrel staves and other similar parts.[16]
These fasteners are "screws" according to the Machinery's Handbook criteria, and the obsolescent term "lag bolt" has been replaced by "lag screw" in the Handbook.[17] However, in the minds of many tradesmen, they are "bolts", simply because they are large, with hex or square heads.
The federal government of the United States made an effort to formalize the difference between a bolt and a screw, because different tariffs apply to each.[18] The document seems to have no significant effect on common usage and does not eliminate the ambiguous nature of the distinction between screws and bolts for some threaded fasteners. The document also reflects (although it probably did not originate) significant confusion of terminology usage that differs between the legal/statutory/regulatory community and the fastener industry. The legal/statutory/regulatory wording uses the terms "coarse" and "fine" to refer to the tightness of the tolerance range, referring basically to "high-quality" or "low-quality", but this is a poor choice of terms, because those terms in the fastener industry have a different meaning (referring to the steepness of the helix's lead).
Old USS and SAE standards defined cap screws as fasteners with shanks that were threaded to the head and bolts as fasteners with shanks that were partially unthreaded.[19] The relationship of this rule to the idea that a bolt by definition takes a nut is clear (because the unthreaded section of the shank, which is called the grip, was expected to pass through the substrate without threading into it). This is now an obsolete distinction, although large bolts still often have unthreaded sections of shank.
Although there is no reason to consider this definition obsolete, because it is far from clear that "a bolt by definition takes a nut" . Using a coach "bolt" as an example (and it has been a 'bolt' for a very long time). It was not originally intended to receive a nut, but did have a shank. Its purpose was not to pass through the entire substrate but only one piece of it, while the threaded portion bit into the other in order to draw, and clamp the materials together. The 'carriage' bolt was derived from this and was employed more to speed up manufacturing than achieve a different function. The carriage bolt passes through both pieces of materials and employs a nut to provide the clamping force. Both are still, however, bolts.
The distinctions above are enforced in the controlled vocabulary of standards organizations. Nevertheless, there are sometimes differences between the controlled vocabulary and the natural language use of the words by machinists, auto mechanics and others. These differences reflect linguistic evolution shaped by the changing of technology over centuries. The words bolt and screw have both existed since before today's modern mix of fastener types existed, and the natural usage of those words has evolved retronymously in response to the technological change. (That is, the use of words as names for objects changes as the objects change.) Non-threaded fasteners predominated until the advent of practical, inexpensive screw-cutting in the early 19th century. The basic meaning of the word screw has long involved the idea of a helical screw thread, but the Archimedes screw and the screw gimlet (like a corkscrew) preceded the fastener.
The word bolt is also a very old word, and it was used for centuries to refer to metal rods that passed through the substrate to be fastened on the other side, often via nonthreaded means (clinching, forge welding, pinning, wedging, etc.). The connection of this sense to the sense of a door bolt or the crossbow bolt is apparent. In the 19th century, bolts fastened via screw threads were often called screw bolts in contradistinction to clench bolts.
In common usage, the distinction (not rigorous) is often that screws are smaller than bolts, and that screws are generally tapered while bolts are not. For example, cylinder head bolts are called "bolts" (at least in North American usage) despite the fact that by some definitions they ought to be called "screws". Their size and their similarity to a bolt that would take a nut seem linguistically to overrule any other factors in this natural word choice proclivity.
Bolts have been defined as headed fasteners having external threads that meet an exacting, uniform bolt thread specification (such as ISO metric screw thread M, MJ, Unified Thread Standard UN, UNR, and UNJ) such that they can accept a non-tapered nut. Screws are then defined as headed, externally threaded fasteners that do not meet the above definition of bolts.[citation needed] These definitions of screw and bolt eliminate the ambiguity of the Machinery's handbook distinction. And it is for that reason, perhaps, that some people favor them. However, they are neither compliant with common usage of the two words nor are they compliant with formal specifications.
A possible distinction is that a screw is designed to cut its own thread; it has no need for access from or exposure to the opposite side of the component being fastened to. This definition of screw is further reinforced by the consideration of the developments of fasteners such as Tek Screws, with either round or hex heads, for roof cladding, self-drilling and self-tapping screws for various metal fastening applications, roof batten screws to reinforce the connection between the roof batten and the rafter, decking screws etc. On the other hand, a bolt is the male part of a fastener system designed to be accepted by a pre-equipped socket (or nut) of exactly the same thread design.
Threaded fasteners either have a tapered shank or a non-tapered shank. Fasteners with tapered shanks are designed to either be driven into a substrate directly or into a pilot hole in a substrate. Mating threads are formed in the substrate as these fasteners are driven in. Fasteners with a non-tapered shank are designed to mate with a nut or to be driven into a tapped hole.
|American name
|British name
| chipboard screw
particle board screw
|Similar to a drywall screw except that it has a thinner shank and provides better resistance to pull-out in particle board, while offset against a lower shear strength. The threads on particle board screws are asymmetrical.
| concrete screw
masonry screw
confast screw
multi-material screw
blue screw
self-tapping masonry screw
|A stainless or carbon steel screw for fastening wood, metal, or other materials to concrete or masonry. Concrete screws are commonly blue in color, with or without corrosion coating.[20] They may either have a Phillips flat head or a slotted hex washer head. Nominal (thread) sizes range from 0.1875 to 0.375 in (4.763 to 9.525 mm) and lengths from 1.25 to 5 in (32 to 127 mm). Typically an installer uses a hammer drill to make a pilot hole for each concrete screw and a powered impact driver to drive the screw.
|deck screw
|Similar to drywall screw except that it has improved corrosion resistance and is generally supplied in a larger gauge. Most deck screws have a type-17 (auger type) thread cutting tip for installation into decking materials. They have bugle heads that allows the screw to depress the wood surface without breaking it.
| double ended screw
dowel screw
hanger bolt
|handrail bolt
| Similar to a wood screw but with two pointed ends and no head, used for making hidden joints between two pieces of wood.
A hanger bolt has wood screw threads on one end and machine threads on the other. A hanger bolt is used when it is necessary to fasten a metal part to a wood surface.
| drive screw
hammer drive screw
|Chiefly used for attaching manufacturers data plates to equipment. Smooth round or mushroom headed with a multi-start thread on the shank, beneath which is reduced diameter shank that acts as a pilot. The screw is fastened by hitting the head with a hammer and is not intended for removal.[21]
|drywall screw
|Specialized screw with a bugle head that is designed to attach drywall to wood or metal studs, however it is a versatile construction fastener with many uses. The diameter of drywall screw threads is larger than the grip diameter.
| eye screw
screw eye
vine eye
| Screw with a looped head. Larger ones are sometimes called lag eye screws. Designed to be used as attachment point, particularly for something that is hung from it.
A vine eye (in the UK at least) is similar to a screw eye, except that it has a proportionally longer shank and smaller looped head. As the term suggests vine eyes are often used for attaching wire lines across the surface of buildings so that climbing plants can attach themselves.
| lag bolt
lag screw[22]
|coach screw
| Similar to a wood screw except that it is generally much larger running to lengths up to 15 in (381 mm) with diameters from 0.25–0.5 in (6.35–12.70 mm) in commonly available (hardware store) sizes (not counting larger mining and civil engineering lags and lag bolts) and it generally has a hexagonal drive head. Lag bolts are designed for securely fastening heavy timbers (post and beams, timber railway trestles and bridges) to one another, or to fasten wood to masonry or concrete.
Lag bolts are usually used with an expanding insert called a lag in masonry or concrete walls, the lag manufactured with a hard metal jacket that bites into the sides of the drilled hole, and the inner metal in the lag being a softer alloy of lead, or zinc alloyed with soft iron. The coarse thread of a lag bolt and lag mesh and deform slightly making a secure near water tight anti-corroding mechanically strong fastening.
|mirror screw
|This is a flat-head wood screw with a tapped hole in the head, which receives a screw-in chrome-plated cover. It is usually used to mount a mirror.
|sheet metal screw
|Has sharp threads that cut into a material such as sheet metal, plastic or wood. They are sometimes notched at the tip to aid in chip removal during thread cutting. The shank is usually threaded up to the head. Sheet metal screws make excellent fasteners for attaching metal hardware to wood because the fully threaded shank provides good retention in wood.
|Twinfast screw
|A Twinfast screw is a type of screw with two threads (i.e. a twin-start screw), so that it can be driven twice as fast as a normal (i.e. single-start) screw with the same pitch.[23] Dry wall screws designated as fine are the most common screws to use the twinfast style of threads.[24]
|wood screw
|A metal screw with a sharp point designed to attach two pieces of wood together. Wood screws are commonly available with flat, pan or oval-heads. A wood screw generally has a partially unthreaded shank below the head. The unthreaded portion of the shank is designed to slide through the top board (closest to the screw head) so that it can be pulled tight to the board to which it is being attached.
|Security head screw
|These screws are use for security purposes and where vandalism and/or theft is likely. The head of this type of screw is impossible to reverse. It requires special tools or mechanisms like spanners, tri-wings, torxes, square drivers, etc. In some screws, the head can be removed by breaking it after installing the screw.
|American name
|British name
|anchor bolt
|A special type of bolt that is set in wet concrete, with the screw threads protruding above the concrete surface.
|breakaway bolt
|A breakaway bolt is a bolt with a hollow threaded shank, which is designed to break away upon impact. Typically used to fasten fire hydrants, so they will break away when hit by a car. Also used in aircraft to reduce weight.
|cap screw
| The term cap screw refers to many different things at different times and places. Currently, it most narrowly refers to a style of head (see the gallery below). More broadly, and more commonly, it refers to the group of screws: shoulder screws, hex heads, counter-sunk heads, button heads, and fillister heads. In the United States, cap screws are defined by ASME B18.6.2 and ASME B18.3.[25][26] In the past, the term cap screw, in general, referred to screws that were supposed to be used in applications where a nut was not used, however the characteristics that differentiated it from a bolt vary over time. In 1910, Anthony defined it as screw with a hex head that was thicker than a bolt head, but the distance across the flats was less than a bolt's.[27] In 1913, Woolley and Meredith defined them like Anthony, but gave the following dimensions: hex head cap screws up to and including 7⁄16 inch (11.1125 mm) have a head that is 3⁄16 inch (4.7625 mm) larger than the shank diameter; screws greater than 1⁄2 inch (12.7 mm) in diameter have a head that is 1⁄4 inch (6.35 mm) larger than the shank. Square head cap screws up to and including 3⁄4 inch (19.05 mm) have a head 1⁄8 inch (3.175 mm) larger than the shank; screws larger than 3⁄4 inch (19.05 mm) have a head 1⁄4 inch (6.35 mm) larger than the shank.[28] In 1919, Dyke defined them as screws that are threaded all the way to the head.[19]
A socket cap screw, also known as a socket head capscrew, socket screw, or Allen bolt, is a type of cap screw with a cylindrical head and hexagonal drive hole. The term socket head capscrew typically refers to a type of threaded fastener whose head diameter is nominally 1.5 times that of the screw shank (major) diameter, with a head height equal to the shank diameter (1960 series design). Forged heat-treated alloy examples are high strength fasteners intended for the most demanding mechanical applications, with special alloy formulations available that are capable of maintaining strength at temperatures in excess of 1000 degrees F (587 degrees C).
In addition to the 1960 series design, other head designs include low head, button head and flat head, the latter designed to be seated into countersunk holes. A hex key (sometimes referred to as an Allen wrench or Allen key) or hex driver is required to tighten or loosen a socket screw. Socket head capscrews are commonly used in assemblies that do not provide sufficient clearance for a conventional wrench or socket.
|carriage bolt
|cup head bolt, coach bolt
|A carriage bolt, also known as a coach bolt, has a domed or countersunk head, and the shank is topped by a short square section under the head. The square section grips into the part being fixed (typically wood), preventing the bolt from turning when the nut is tightened. Carriage bolts are used to provide a smooth finish on automobile metal bumper exteriors, the square section aligning with a square hole in the bumper to provide anti-rotation. A rib neck carriage bolt has several longitudinal ribs instead of the square section, to grip into a metal part being fixed.
|elevator bolt
|An elevator bolt is a bolt similar to a carriage bolt, except the head is thin and flat. There are many variations. Some do not have a square base, but rather triangular sections of the flat head are folded down to form "fangs" that cut into wood and hold it secure.[29]
|eye bolt
|An eye bolt is a bolt with a looped head.
| hex cap screw
hex bolt
|A hex cap screw is a cap screw with a hexagonal head, designed to be driven by a wrench (spanner). An ASME B18.2.1 compliant cap screw has somewhat tighter tolerances than a hex bolt for the head height and the shank length. The nature of the tolerance difference allows an ASME B18.2.1 hex cap screw to always fit where a hex bolt is installed but a hex bolt could be slightly too large to be used where a hex cap screw is designed in.
|Fine adjustment screw
|The term fine adjustment screw typically refers to screws with threads from 40–100 TPI (Threads Per Inch) (0.5mm to 0.2mm pitch) and ultra fine adjustment screw has been used to refer to 100–254 TPI (0.2mm to 0.1mm pitch). These screws are most frequently used in applications where the screw is used to control fine motion of an object.
|machine screw
|A machine screw is generally a smaller fastener (less than 1⁄4 inch (6.35 mm) in diameter) threaded the entire length of its shank that usually has a recessed drive type (slotted, Phillips, etc.). Machine screws are also made with socket heads (see above), in which case they may be referred to as socket head machine screws.
|plow bolt
|plough bolt
|A plow bolt is bolt similar to a carriage bolt, except the head is flat or concave, and the underside of the head is a cone designed to fit in a countersunk recess. Plow bolts provide a smooth surface for attaching a plow moldboard to its beam, where a raised head would suffer from soil abrasion. There are many variations, with some not using a square base, but rather a key, a locking slot, or other means. The recess in the mating part must be designed to accept the particular plow bolt. ASME B18.9 standard recommends a No. 3 head (round countersunk head square neck) plow bolts and No. 7 head (round countersunk reverse key head) plow bolts for new designs. The necessary dimensions for the head styles can be found in the standard.[30][31][32]
| self-drilling screw
Teks screw
|Similar to a sheet metal screw, but it has a drill-shaped point to cut through the substrate to eliminate the need for drilling a pilot hole. Designed for use in soft steel or other metals. The points are numbered from 1 through 5, the larger the number, the thicker metal it can go through without a pilot hole. A 5-point can drill a 0.5 in (12.7 mm) of steel, for example.
|self-tapping machine screw
|A self-tapping machine screw is similar to a machine screw except the lower part of the shank is designed to cut threads as the screw is driven into an untapped hole. The advantage of this screw type over a self-drilling screw is that, if the screw is reinstalled, new threads are not cut as the screw is driven.
|set bolt
|tap bolt
|A bolt that is threaded all the way to the head. An ASME B18.2.1 compliant set/tap bolt has the same tolerances as an ASME B18.2.1 compliant hex cap screw.
|set screw
|grub screw
|A set screw is generally a headless screw but can be any screw used to fix a rotating part to a shaft, such as a line shaft or countershaft. The set screw is driven through a threaded hole in the rotating part until it is tight against the shaft. The most often used type is the socket set screw, which is tightened or loosened with a hex key.
| shoulder bolt
shoulder screw
|stripper bolt
|A shoulder screw differs from machine screws in that the shank is held to a precise diameter, known as the shoulder, and the threaded portion is smaller in diameter than the shoulder. Shoulder screw specifications call out the shoulder diameter, shoulder length, and threaded diameter; the threaded length is fixed, based on the threaded diameter, and usually quite short. Shoulder screws can be manufactured in many materials such as alloy heat-treated steel for maximum strength and wear resistance and stainless steel for its corrosion-resistance and non-magnetic properties. Common applications for shoulder screws include rotating mechanism joints, linkage pivots, and guides for the stripper plate of a metal forming die set. In the latter application, the term stripper bolt is often substituted. Stainless steel shoulder screws are used with linear motion devices such as bearings, as guides and as pivots in electronic and other critical mechanical applications.
|stove bolt
|gutter bolt
|A stove bolt is a type of machine screw that has a round or flat head and is threaded to the head. They are usually made of low grade steel, have a slot or Phillips drive, and are used to join sheet metal parts using a hex or square nut.[33]
|tension control bolt
|A tension control bolt (TC bolt) is a heavy duty bolt used in steel frame construction. The head is usually domed and is not designed to be driven. The end of the shank has a spline on it which is engaged by a special power wrench which prevents the bolt from turning while the nut is tightened. When the appropriate torque is reached the spline shears off.
|thread rolling screws
|These have a lobed (usually triangular) cross-section. They form threads in a pre-existing hole in the mating workpiece by pushing the material outward during installation. In some cases the properly prepared hole in sheetmetal uses an extruded hole. The extrusion forms a lead-in and extra thread length for improved retention. Thread rolling screws are often used where loose chips formed by a thread cutting operation cannot be tolerated.
A fastener with a built in washer is called a SEM or SEMS, short for pre-asSEMbled.[34][35] It could be fitted on either a tapered or non-tapered shank.
A superbolt, or multi-jackbolt tensioner is an alternative type of fastener that retrofits or replaces existing nuts, bolts, or studs. Tension in the bolt is developed by torquing individual jackbolts, which are threaded through the body of the nut and push against a hardened washer. Because of this, the amount of torque required to achieve a given preload is reduced. Installation and removal of any size tensioner is achieved with hand tools, which can be advantageous when dealing with large diameter bolting applications.
The field of screws and other hardware for internal fixation within the body is huge and diverse. Like prosthetics, it integrates the industrial and medicosurgical fields, causing manufacturing technologies (such as machining, CAD/CAM, and 3D printing) to intersect with the art and science of medicine. Like aerospace and nuclear power, this field involves some of the highest technology for fasteners, as well as some of the highest prices, for the simple reason that performance, longevity, and quality have to be excellent in such applications. Bone screws tend to be made of stainless steel or titanium, and they often have high-end features such as conical threads, multistart threads, cannulation (hollow core), and proprietary screw drive types (some not seen outside of these applications).
These abbreviations have jargon currency among fastener specialists (who, working with many screw types all day long, have need to abbreviate repetitive mentions). The smaller basic ones can be built up into the longer ones; for example, if you know that "FH" means "flat head", then you may be able to parse the rest of a longer abbreviation containing "FH".
These abbreviations are not universally standardized across corporations; each corporation can coin their own. The more obscure ones may not be listed here.
The extra spacing between linked terms below helps the reader to see the correct parsing at a glance.
|button head
|button head cap screw
|button head machine screw
|cap screw
|flat head
|flat head Phillips
|flat head socket cap screw
|flat head Phillips machine screw
|full thread
|hex head cap screw
|Hexalobular socket head cap screws
|machine screw
|oval head
|Phillips head
|round head
|round head machine screw
|round head Phillips
|round head Phillips machine screw
|socket button head cap screw
|socket button head machine screw
|socket head
|Although "socket head" could logically refer to almost any female drive, it refers by convention to hex socket head unless further specified
|socket head cap screw
|socket head set screw
|set screw
|The abbreviation "SS" more often means stainless steel. Therefore, "SS cap screw" means "stainless steel cap screw" but "SHSS" means "socket head set screw". As with many abbreviations, users rely on context to diminish the ambiguity, although this reliance does not eliminate it.
|self-tapping screw
Screws and bolts are usually made of steel. Where great resistance to weather or corrosion is required, like in very small screws or medical implants, materials such as stainless steel, brass, titanium, bronze, silicon bronze or monel may be used.
Galvanic corrosion of dissimilar metals can be prevented (using aluminum screws for double-glazing tracks for example) by a careful choice of material. Some types of plastic, such as nylon or polytetrafluoroethylene (PTFE), can be threaded and used for fastenings requiring moderate strength and great resistance to corrosion or for the purpose of electrical insulation.
Often a surface coating is used to protect the fastener from corrosion (e.g. bright zinc plating for steel screws), to impart a decorative finish (e.g. japanning) or otherwise alter the surface properties of the base material.
Selection criteria of the screw materials include: size, required strength, resistance to corrosion, joint material, cost and temperature.
The American Institute of Steel Construction (AISC) 13th Edition Steel Design Manual section 16.1 chapter J-3 specifies the requirements for bolted structural connections. Structural bolts replaced rivets due to decreasing cost and increasing strength of structural bolts in the 20th century. Connections are formed with two types of joints: slip-critical connections and bearing connections. In slip-critical connections, movement of the connected parts is a serviceability condition and bolts are tightened to a minimum required pretension. Slip is prevented through friction of the "faying" surface, that is the plane of shear for the bolt and where two members make contact. Because friction is proportional to the normal force, connections must be sized with bolts numerous and large enough to provide the required load capacity. However, this greatly decreases the shear capacity of each bolt in the connection. The second type and more common connection is a bearing connection. In this type of connection the bolts carry the load through shear and are only tightened to a "snug-fit". These connections require fewer bolts than slip-critical connections and therefore are a less expensive alternative. Slip-critical connections are more common on flange plates for beam and column splices and moment critical connections. Bearing type connections are used in light weight structures and in member connections where slip is not important and prevention of structural failure is the design constraint. Common bearing type connections include: shear tabs, beam supports, gusset plates in trusses.
The numbers stamped on the head of the bolt are referred to the grade of the bolt used in certain application with the strength of a bolt. High-strength steel bolts usually have a hexagonal head with an ISO strength rating (called property class) stamped on the head. And the absence of marking/number indicates a lower grade bolt with low strength. The property classes most often used are 5.8, 8.8, and 10.9. The number before the point is the ultimate tensile strength in MPa divided by 100. The number after the point is the multiplier ratio of yield strength to ultimate tensile strength. For example, a property class 5.8 bolt has a nominal (minimum) ultimate tensile strength of 500 MPa, and a tensile yield strength of 0.8 times ultimate tensile strength or 0.8(500) = 400 MPa.
Ultimate tensile strength is the tensile stress at which the bolt fails. Tensile yield strength is the stress at which the bolt will yield in tension across the entire section of the bolt and receive a permanent set (an elongation from which it will not recover when the force is removed) of 0.2% offset strain. Proof strength is the usable strength of the fastener. Tension testing of a bolt up to the proof load should not cause permanent set of the bolt and should be conducted on actual fasteners rather than calculated.[36] If a bolt is tensioned beyond the proof load, it may behave in plastic manner due to yielding in the threads and the tension preload may be lost due to the permanent plastic deformations. When elongating a fastener prior to reaching the yield point, the fastener is said to be operating in the elastic region; whereas elongation beyond the yield point is referred to as operating in the plastic region of the bolt material. If a bolt is loaded in tension beyond its proof strength, the yielding at the net root section of the bolt will continue until the entire section is begins to yield and it has exceeded its yield strength. If tension increases, the bolt fractures at its ultimate strength.
Mild steel bolts have property class 4.6, with is 400 MPa ultimate strength and 0.6*400=240 MPa yield strength. High-strength steel bolts have property class 8.8, which is 800 MPa ultimate strength and 0.8*800=640 MPa yield strength or above.
The same type of screw or bolt can be made in many different grades of material. For critical high-tensile-strength applications, low-grade bolts may fail, resulting in damage or injury. On SAE-standard bolts, a distinctive pattern of marking is impressed on the heads to allow inspection and validation of the strength of the bolt.[37] However, low-cost counterfeit fasteners may be found with actual strength far less than indicated by the markings. Such inferior fasteners are a danger to life and property when used in aircraft, automobiles, heavy trucks, and similar critical applications.[38]
SAE J429 defines the bolt grades for inch-system sized bolts and screws. It defines them by grade, which ranges from 0 to 8, with 8 being the strongest. Higher grades do not exist within the specification.[39][40] SAE grades 5 and 8 are the most common.
|Head markings and properties for inch-system hex-head cap screws[41]
|Head marking
|Grade, material and condition
|Nominal size range (in)
|Proof strength
|Yield strength, min.
|Tensile strength, min.
|Core hardness (Rockwell)
|SAE Grade 0[39]
|Strength and hardness is not specified
| SAE grade 1
Low carbon steel
|1⁄4–1- 1⁄2
| ASTM A307 - Grade B[42]
Low or medium carbon steel
|60 minimum
100 maximum
|410 minimum
690 maximum
| SAE grade 2
Low or medium carbon steel
|1⁄4– 3⁄4
|Greater than 3⁄4
| SAE grade 4[44]
Medium carbon steel; cold worked
|1⁄4–1- 1⁄2
| SAE grade 3[42]
Medium carbon steel; cold worked
| SAE grade 5
Medium carbon steel; quench and tempered
|1⁄4–1 (inc.)
|1–1- 1⁄2
| ASTM A449 - Type 1[42]
Medium carbon steel; quench and tempered
|1–1- 1⁄2 (inc.)
|1- 1⁄2–3
|Brinell 183–235
| SAE grade 5.1[45]
Low or medium carbon steel; quench and tempered
|No. 6– 1⁄2
| SAE grade 5.2[45]
Low carbon martensitic steel; quench and tempered
| ASTM A449 - Type 2[45]
Low carbon martensitic steel; quench and tempered
| ASTM A325 - Type 1[42]
Medium carbon steel; quench and tempered
|1⁄2–1 (inc.)
|1–1- 1⁄2
| ASTM A325 - Type 3[42]
Atmospheric corrosion resistant steel; quench and tempered
|1–1- 1⁄2
| ASTM A354 - Grade BC[42]
Medium carbon alloy steel; quench and tempered
|1⁄4–2- 1⁄2 (inc.)
|2- 1⁄2–4
| SAE grade 7
Medium carbon alloy steel; quench and tempered
|1⁄4–1- 1⁄2
| SAE grade 8
Medium carbon alloy steel; quench and tempered
|1⁄4–1- 1⁄2
|ASTM A354 - Grade BD[47]
|1⁄4–2- 1⁄2 (inc.)
|2- 1⁄2–4
| SAE grade 8.2[43]
Medium carbon boron martensitic steel; fully kilned, fine grain, quench and tempered
| ASTM A490 - Type 1[42]
Medium carbon alloy steel; quench and tempered
|1⁄2–1- 1⁄2
|150 minimum
170 maximum
|1,000 minimum
1,200 maximum
| ASTM A490 - Type 3[42]
Atmospheric corrosion resistant steel; quench and tempered
| 18/8 Stainless
Stainless steel with 17–19% chromium and 8–13% nickel
|1⁄4– 5⁄8 (inc.)
|40 minimum
80–90 typical
|280 minimum
550–620 typical
|100–125 typical
|690–860 typical
|5⁄8–1 (inc.)
|40 minimum
45–70 typical
|280 minimum
310–480 typical
|100 typical
|690 typical
|over 1
|80–90 typical
|550–620 typical
The international standard for metric screws is defined by ISO 898, specifically ISO 898-1.
|Head markings and properties for metric hex-head cap screws[48]
|Head marking
|Grade, material and condition
|Nominal size range (mm)
|Proof strength
|Yield strength, min.
|Tensile strength, min.
|Core hardness (Rockwell)
|Class 3.6[49]
| Class 4.6
Low or medium carbon steel
| Class 4.8
Low or medium carbon steel; fully or partially annealed
| Class 5.8
Low or medium carbon steel; cold worked
| Class 8.8[41]
Medium carbon steel; quench and tempered
|Under 16 (inc.)
| Class 8.8 low carbon
Low carbon boron steel; quench and tempered
| Class 8.8.3[50]
Atmospheric corrosion resistant steel; quench and tempered
| ASTM A325M - Type 1[51][52]
Medium carbon steel; quench and tempered
| ASTM A325M - Type 3[51][52]
Atmospheric corrosion resistant steel; quench and tempered
| Class 9.8
Medium carbon steel; quench and tempered
| Class 9.8 low carbon
Low carbon boron steel; quench and tempered
| Class 10.9
Alloy steel; quench and tempered
| Class 10.9 low carbon
Low carbon boron steel; quench and tempered
| Class 10.9.3[50]
Atmospheric corrosion resistant steel; quench and tempered
| ASTM A490M - Type 1[51][53]
Alloy steel; quench and tempered
| ASTM A490M - Type 3[51][53]
Atmospheric corrosion resistant steel; quench and tempered
| Class 12.9
Alloy steel; quench and tempered
Stainless steel with 17–19% chromium and 8–13% nickel
|up to 20
| 210 minimum
450 typical
| 30 minimum
65 typical
| 500 minimum
700 typical
| 73 minimum
100 typical
| ISO 3506-1 A2-50[citation needed]
304 stainless steel-class 50 (annealed)
| ISO 3506-1 A2-70[citation needed]
304 stainless steel-class 70 (cold worked)
| ISO 3506-1 A2-80[citation needed]
304 stainless steel-class 80
Some varieties of screw are manufactured with a break-away head, which snaps off when adequate torque is applied. This prevents tampering and also provides an easily inspectable joint to guarantee proper assembly. An example of this is the shear bolts used on vehicle steering columns, to secure the ignition switch.
|Part of a series on
|Screw drive types
|Pozidriv (SupaDriv)
|12-point flange
|Hex socket (Allen)
|Security hex socket (pin-in-hex-socket)
|Security Torx
|Spanner head
(pig nose)
|Spline drive
|Double hex
Modern screws employ a wide variety of drive designs, each requiring a different kind of tool to drive in or extract them. The most common screw drives are the slotted and Phillips in the US; hex, Robertson, and Torx are also common in some applications, and Pozidriv has almost completely replaced Phillips in Europe. Some types of drive are intended for automatic assembly in mass-production of such items as automobiles. More exotic screw drive types may be used in situations where tampering is undesirable, such as in electronic appliances that should not be serviced by the home repair person.
The hand tool used to drive in most screws is called a screwdriver. A power tool that does the same job is a power screwdriver; power drills may also be used with screw-driving attachments. Where the holding power of the screwed joint is critical, torque-measuring and torque-limiting screwdrivers are used to ensure sufficient but not excessive force is developed by the screw. The hand tool for driving hex head threaded fasteners is a spanner (UK usage) or wrench (US usage), while a nut setter is used with a power screw driver.
|This article appears to contradict the article Screw thread. (February 2010) (Learn how and when to remove this template message)
There are many systems for specifying the dimensions of screws, but in much of the world the ISO metric screw thread preferred series has displaced the many older systems. Other relatively common systems include the British Standard Whitworth, BA system (British Association), and the Unified Thread Standard.
The basic principles of the ISO metric screw thread are defined in international standard ISO 68-1 and preferred combinations of diameter and pitch are listed in ISO 261. The smaller subset of diameter and pitch combinations commonly used in screws, nuts and bolts is given in ISO 262. The most commonly used pitch value for each diameter is the coarse pitch. For some diameters, one or two additional fine pitch variants are also specified, for special applications such as threads in thin-walled pipes. ISO metric screw threads are designated by the letter M followed by the major diameter of the thread in millimeters (e.g. M8). If the thread does not use the normal coarse pitch (e.g. 1.25 mm in the case of M8), then the pitch in millimeters is also appended with a multiplication sign (e.g. "M8×1" if the screw thread has an outer diameter of 8 mm and advances by 1 mm per 360° rotation).
The nominal diameter of a metric screw is the outer diameter of the thread. The tapped hole (or nut) into which the screw fits, has an internal diameter which is the size of the screw minus the pitch of the thread. Thus, an M6 screw, which has a pitch of 1 mm, is made by threading a 6 mm shank, and the nut or threaded hole is made by tapping threads into a hole of 5 mm diameter (6 mm - 1 mm).
Metric hexagon bolts, screws and nuts are specified, for example, in British Standard BS 4190 (general purpose screws) and BS 3692 (precision screws). The following table lists the relationship given in these standards between the thread size and the maximal width across the hexagonal flats (wrench size):
|ISO metric thread
|Wrench size (mm)
In addition, the following non-preferred intermediate sizes are specified:
|ISO metric thread
|Wrench size (mm)
The first person to create a standard (in about 1841) was the English engineer Sir Joseph Whitworth. Whitworth screw sizes are still used, both for repairing old machinery and where a coarser thread than the metric fastener thread is required. Whitworth became British Standard Whitworth, abbreviated to BSW (BS 84:1956) and the British Standard Fine (BSF) thread was introduced in 1908 because the Whitworth thread was too coarse for some applications. The thread angle was 55°, and the depth and pitch varied with the diameter of the thread (i.e., the bigger the bolt, the coarser the thread). Spanners for Whitworth bolts are marked with the size of the bolt, not the distance across the flats of the screw head.
The most common use of a Whitworth pitch nowadays is in all UK scaffolding. Additionally, the standard photographic tripod thread, which for small cameras is 1/4" Whitworth (20 tpi) and for medium/large format cameras is 3/8" Whitworth (16 tpi). It is also used for microphone stands and their appropriate clips, again in both sizes, along with "thread adapters" to allow the smaller size to attach to items requiring the larger thread. Note that while 1/4" UNC bolts fit 1/4" BSW camera tripod bushes, yield strength is reduced by the different thread angles of 60° and 55° respectively.
British Association (BA) screw threads, named after the British Association for Advancement of Science, were devised in 1884 and standardised in 1903. Screws were described as "2BA", "4BA" etc., the odd numbers being rarely used, except in equipment made prior to the 1970s for telephone exchanges in the UK. This equipment made extensive use of odd-numbered BA screws, in order—it may be suspected—to reduce theft. BA threads are specified by British Standard BS 93:1951 "Specification for British Association (B.A.) screw threads with tolerances for sizes 0 B.A. to 16 B.A."
While not related to ISO metric screws, the sizes were actually defined in metric terms, a 0BA thread having a 6 mm diameter and 1 mm pitch. Other threads in the BA series are related to 0BA in a geometric series with the common factors 0.9 and 1.2. For example, a 4BA thread has pitch mm (0.65mm) and diameter mm (3.62mm). Although 0BA has the same diameter and pitch as ISO M6, the threads have different forms and are not compatible.
BA threads are still common in some niche applications. Certain types of fine machinery, such as moving-coil meters and clocks, tend to have BA threads wherever they are manufactured. BA sizes were also used extensively in aircraft, especially those manufactured in the United Kingdom. BA sizing is still used in railway signalling, mainly for the termination of electrical equipment and cabling.
BA threads are extensively used in Model Engineering where the smaller hex head sizes make scale fastenings easier to represent. As a result, many UK Model Engineering suppliers still carry stocks of BA fasteners up to typically 8BA and 10BA. 5BA is also commonly used as it can be threaded onto 1/8 rod.[56]
The Unified Thread Standard (UTS) is most commonly used in the United States, but is also extensively used in Canada and occasionally in other countries. The size of a UTS screw is described using the following format: X-Y, where X is the nominal size (the hole or slot size in standard manufacturing practice through which the shank of the screw can easily be pushed) and Y is the threads per inch (TPI). For sizes 1⁄4 inch and larger the size is given as a fraction; for sizes less than this an integer is used, ranging from 0 to 16. The integer sizes can be converted to the actual diameter by using the formula 0.060 + 0.013 × number. For example, a #4 screw is 0.060 + 0.013 × 4 = 0.112 inches in diameter. There are also screw sizes smaller than "0" (zero or ought). The sizes are 00, 000, 0000 which are usually referred to as two ought, three ought, and four ought. Most eyeglasses have the bows screwed to the frame with 00-72 (pronounced double ought – seventy two) size screws. To calculate the major diameter of "ought" size screws count the number of 0's and multiply this number by .013 and subtract from .060. For example, the major diameter of a 000-72 screw thread is .060 – (3 x .013) = .060-.039 = .021 inches. For most size screws there are multiple TPI available, with the most common being designated a Unified Coarse Thread (UNC or UN) and Unified Fine Thread (UNF or UF). Note: In countries other than the United States and Canada, the ISO Metric Screw Thread System is primarily used today. Unlike most other countries the United States and Canada still use the Unified (Inch) Thread System. However, both are moving over to the ISO Metric System. It is estimated that approximately 60% of screw threads in use in the United States are still inch based.[67]
There are three steps in manufacturing a screw: heading, thread rolling, and coating. Screws are normally made from wire, which is supplied in large coils, or round bar stock for larger screws. The wire or rod is then cut to the proper length for the type of screw being made; this workpiece is known as a blank. It is then cold headed, which is a cold working process. Heading produces the head of the screw. The shape of the die in the machine dictates what features are pressed into the screw head; for example a flat head screw uses a flat die. For more complicated shapes two heading processes are required to get all of the features into the screw head. This production method is used because heading has a very high production rate, and produces virtually no waste material. Slotted head screws require an extra step to cut the slot in the head; this is done on a slotting machine. These machines are essentially stripped down milling machines designed to process as many blanks as possible.
The blanks are then polished[citation needed] again prior to threading. The threads are usually produced via thread rolling, however some are cut. The workpiece is then tumble finished with wood and leather media to do final cleaning and polishing.[citation needed] For most screws, a coating, such as electroplating with zinc (galvanizing) or applying black oxide, is applied to prevent corrosion.
While a recent hypothesis attributes the Archimedes' screw to Sennacherib, King of Assyria, archaeological finds and pictorial evidence only appear in the Hellenistic period and the standard view holds the device to be a Greek invention, most probably by the 3rd century BC polymath Archimedes.[57][dubious ] Though resembling a screw, this is not a screw in the usual sense of the word.
Earlier, the screw had been described by the Greek mathematician Archytas of Tarentum (428–350 BC). By the 1st century BC, wooden screws were commonly used throughout the Mediterranean world in screw presses for pressing olive oil from olives and pressing juice from grapes in winemaking. Metal screws used as fasteners were rare in Europe before the 15th century, if known at all.[58]
Rybczynski has shown[59] that handheld screwdrivers (formerly called "turnscrews" in English, in more direct parallel to their original French name, tournevis[60]) have existed since medieval times (the 1580s at the latest), although they probably did not become truly widespread until after 1800, once threaded fasteners had become commodified, as detailed below.[peacock term]
There were many forms of fastening in use before threaded fasteners became widespread. They tended to involve carpentry and smithing rather than machining, and they involved concepts such as dowels and pins, wedging, mortises and tenons, dovetails, nailing (with or without clenching the nail ends), forge welding, and many kinds of binding with cord made of leather or fiber, using many kinds of knots. Prior to the mid-19th century, cotter pins or pin bolts, and "clinch bolts" (now called rivets), were used in shipbuilding. Glues also existed, although not in the profusion seen today.
The metal screw did not become a common fastener until machine tools for their mass production were developed toward the end of the 18th century. This development blossomed in the 1760s and 1770s[61] along two separate paths that soon converged:[62] the mass production of wood screws [meaning screws made of metal to be used in wood] in a specialized, single-purpose, high-volume-production machine tool; and the low-count, toolroom-style production of machine screws (V-thread) with easy selection among various pitches (whatever the machinist happened to need on any given day).
The first path was pioneered by brothers Job and William Wyatt of Staffordshire, UK,[63] who patented in 1760 a machine that we might today best call a screw machine of an early and prescient sort. It made use of a leadscrew to guide the cutter to produce the desired pitch,[63] and the slot was cut with a rotary file while the main spindle held still (presaging live tools on lathes 250 years later). Not until 1776 did the Wyatt brothers have a wood-screw factory up and running.[63] Their enterprise failed, but new owners soon made it prosper, and in the 1780s they were producing 16,000 screws a day with only 30 employees[64]—the kind of industrial productivity and output volume that would later be characteristic of modern industry but was revolutionary at the time.
Meanwhile, English instrument maker Jesse Ramsden (1735–1800) was working on the toolmaking and instrument-making end of the screw-cutting problem, and in 1777 he invented the first satisfactory screw-cutting lathe.[65] The British engineer Henry Maudslay (1771–1831) gained fame by popularizing such lathes with his screw-cutting lathes of 1797 and 1800, containing the trifecta of leadscrew, slide rest, and change-gear gear train, all in the right proportions for industrial machining. In a sense he unified the paths of the Wyatts and Ramsden and did for machine screws what had already been done for wood screws, i.e., significant easing of production spurring commodification. His firm would remain a leader in machine tools for decades afterward. A misquoting of James Nasmyth popularized the notion that Maudslay had invented the slide rest, but this was incorrect; however, his lathes helped to popularize it.
These developments of the 1760–1800 era, with the Wyatts and Maudslay being arguably the most important drivers, caused great increase in the use of threaded fasteners. Standardization of threadforms began almost immediately, but it was not quickly completed; it has been an evolving process ever since. Further improvements to the mass production of screws continued to push unit prices lower and lower for decades to come, throughout the 19th century.[66]
The American development of the turret lathe (1840s) and of automatic screw machines derived from it (1870s) drastically reduced the unit cost of threaded fasteners by increasingly automating the machine tool control. This cost reduction spurred ever greater use of screws.
Throughout the 19th century, the most commonly used forms of screw head (that is, drive types) were simple internal-wrenching straight slots and external-wrenching squares and hexagons. These were easy to machine and served most applications adequately. Rybczynski describes a flurry of patents for alternative drive types in the 1860s through 1890s,[67] but explains that these were patented but not manufactured due to the difficulties and expense of doing so at the time. In 1908, Canadian P. L. Robertson was the first to make the internal-wrenching square socket drive a practical reality by developing just the right design (slight taper angles and overall proportions) to allow the head to be stamped easily but successfully, with the metal cold forming as desired rather than being sheared or displaced in unwanted ways.[67] Practical manufacture of the internal-wrenching hexagon drive (hex socket) shortly followed in 1911.[68][69]
In the early 1930s, the popular Phillips-head screw was invented by American Henry F. Phillips.[70]
Threadform standardization further improved in the late 1940s, when the ISO metric screw thread and the Unified Thread Standard were defined.
Precision screws, for controlling motion rather than fastening, developed around the turn of the 19th century, were one of the central technical advances, along with flat surfaces, that enabled the industrial revolution.[71] They are key components of micrometers and lathes.
Alternative fastening methods are:
This article uses material from the Wikipedia article "", which is released under the Creative Commons Attribution-Share-Alike License 3.0. There is a list of all authors in Wikipedia
AutoCAD, SolidWorks, Autodesk Inventor, FreeCAD, Catia, Siemens NX, PTC Creo, Siemens Solid Edge, Microstation, TurboCAD, Draftsight, IronCAD, Spaceclaim, VariCAD, OnShape, IntelliCAD,T-FLEX, VariCAD, TenadoCAD, ProgeCAD, Cadra, ME10, Medusa, Designspark, KeyCreator, Caddy, GstarCAD, Varimetrix, ASCON Kompas-3D, Free Download, Autocad, 2D Library, DXF, DWG, 2D drawing, 3D digital library, STEP, IGES, 3D CAD Models, 3D files, CAD library, 3D CAD files, BeckerCAD, MegaCAD, Topsolid Missler, Vero VisiCAD, Acis SAT, Cimatron, Cadceus, Solidthinking, Unigraphics, Cadkey, ZWCAD, Alibre, Cocreate, MasterCAM, QCAD.org, QCAD, NanoCAD


text:
Liberty Oilfield Services Inc. (NYSE:LBRT) previous close was $14.14 while the outstanding shares total 163.21M. The firm has a beta of 3.16. LBRT's shares traded higher over the last trading session, gaining 10.75% on 06/21/21. The shares fell to a low of $14.52 before closing at $15.66. Intraday shares traded counted 1.89 million, which was -28.34% lower than its 30-day average trading volume of 1.47M. The stock's Relative Strength Index (RSI) is 56.70, with weekly volatility at 7.83% and ATR at 0.93. The LBRT stock's 52-week price range has touched low of $4.91 and a $17.78 high.
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Investors have identified the Oil & Gas Equipment & Services company Liberty Oilfield Services Inc. as an interesting stock but before investments are made there, an in-depth look at its trading activities will have to be conducted. The share is trading with a market value of around $2.87 billion, the company now has both obstacles and catalysts that affect them and they came from their mode of operations. With the company affected by events currently, it is a perfect time to analyze the numbers behind the firm in order to come up with a rather realistic picture of what this stock is.
Liberty Oilfield Services Inc. (LBRT) Fundamentals that are to be considered.
When analyzing a stock, the first fundamental thing to take into account is the balance sheet. How healthy the balance sheet of a company is will determine if the company will be able to carry out all its financial and non-financial obligations and also keep the faith of its investors. For LBRT, the company has in raw cash 69.53 million on their books with 0.37 million currently as liabilities. How the trend is over time is what investors should be concerned about. The company has a healthy balance sheet as their debt profile has been on an incline. In terms of their assets, the company currently has 583.22 million total, with 393.55 million as their total liabilities.
LBRT were able to record 2.17 million as free cash flow during the 08/03/2021 quarter of the year, this saw their quarterly net cash flow reduce by 0.56 million. In cash movements, the company had a total of 27.53 million as operating cash flow.
Potential earnings growth for Liberty Oilfield Services Inc. (LBRT)
In order to determine the future investment potential for this stock, we will have to analyze key trends that affect it. During the 08/03/2021 quarter of the year, Liberty Oilfield Services Inc. recorded a total of 552.03 million in revenue. This figure implies that they witnessed a quarterly year/year change in their earnings with 14.44% coming in sequential stages and their sales for the 08/03/2021 quarter increasing by 53.34%.
What matters though is how it ends. When the core data for the company is broken down, then the stock sounds interesting. The company spent 498.94 million trying to sell their products during the last quarter, with the result yielding a gross income of 53.1 million. This allows shareholders to hold on to 163.21M with the recently reported earning now reading -0.24 cents per share. This is a figure that compared to analyst's prediction for their 08/03/2021 (-0.21 cents a share).
Having a look at the company's valuation, the company is expected to record 0.54 total earnings per share during the next fiscal year. It is very important though to remember that the importance of trend far outweighs that of outlook. This analysis has been great and getting further updates on LBRT sounds very interesting.
Is the stock of LBRT attractive?
In related news, Director, Riverstone/Carlyle Energy Part sold 12,299,996 shares of the company's stock in a transaction that recorded on Jun 10. The sale was performed at an average price of 15.20, for a total value of 186,959,939. As the sale deal closes, the President, Gusek Ron now sold 25,000 shares of the company's stock, valued at 426,350. Also, President, Gusek Ron sold 25,000 shares of the company's stock in a deal that was recorded on Jun 02. The shares were price at an average price of 16.75 per share, with a total market value of 418,750. Following this completion of acquisition, the Chairman of the Board & CEO, Wright Christopher A now holds 30,000 shares of the company's stock, valued at 511,645. In the last 6 months, insiders have changed their ownership in shares of company stock by 3.90%.
6 out of 14 analysts covering the stock have rated it a Buy, while 6 have maintained a Hold recommendation on Liberty Oilfield Services Inc.. 1 analysts has assigned a Sell rating on the LBRT stock. The 12-month mean consensus price target for the company's shares has been set at $14.35.

subset: commoncrawl


text:
Collection: Sewing Machines
For sewing, quilting, embroidery and serging Necchi machines are . . . so perfectly built
In 1919 Vittorio Necchi, of Italy's famous Necchi manufacturing family, returned from WWI to take his place running their cast iron foundry in Pavia. He soon saw that the business world was rapidly changing and the family business would need explore a new direction. When his wife asked him to buy her a sewing machine, her only choices were imported models made in the U.S. and northern Europe. Vittorio had an idea: why not create Italy's first sewing machines company?
Vittorio set up his first sewing machine production facility with 40 workers and by 1924 had produced his first model, the Necchi BD. Initially sales were small, but with persistence and constant improvement Necchi soon introduced the BU model with advanced features like a zig zag stitch. Sales began to take off.
By 1946 the Necchi Sewing Machine Company was producing 1,000 machines a day, employing 4,500 workers, and selling to more than 10,000 retailers. Now the U.S. and the rest of Europe were importing these high quality Italian machines.
Throughout the 20th century the company continued to innovate with Necchi sewing machines like the boldly futuristic Logica and the elegant Mirella, which is part of the permanent collection at the Museum of Modern Art in New York City.
Today, Necchi continues Vittorio's tradition of excellent quality and innovative design. Sewists the world over love Necchi machines for their reliable performance and excellent value.
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Undeterred by the disastrous commando raid on Yemen in the first days of his Administration, where plenty of civilians were killed but the target got away, President Donald Trump has escalated US military involvement in the tragic Yemen conflict to an unprecedented level. In fact as Foreign Policy reports, the US President has bombed Yemen more in the past week than President Obama (no peacenik) has bombed in a year.
But although the US escalation in Yemen is sold back home as another aggressive front in the war against al-Qaeda, in fact US operations in Yemen are actually helping al-Qaeda as well as its chief sponsor, Saudi Arabia.
The problem is that because his advisors are increasingly drawn from the neocon camp, the advice he is given is filtered through the "noble lie" that the neocons view as the central tenet of their faith. Thus even though the main enemies of al-Qaeda in Yemen are the Houthis, because Trump has been sold the neocon lie that the Houthis are Iranian proxies Trump is droning Yemen back to the stone age to the advantage of al-Qaeda and Saudi Arabia, who are on the same side.
While it is arguable that the President has authority under the authorization for the use of military force against those attacked us on 9/11 to attack al-Qaeda in Yemen, very few would argue that such authorization extends to actually helping al-Qaeda in Yemen.
Meanwhile, US drone attacks are killing civilians in Yemen and contributing to the genocide of the Yemeni people whose only crime is to have rejected a president who ran unopposed – a US-backed "Arab Spring" candidate – and who immediately approved US drone strikes on his own country.
The Trump State Department is going all in. A sale of anti-Houthi weapons to Saudi Arabia that even the Obama administration rejected was hastily approved by the new Administration and soon will be deployed in Saudi Arabia's war of aggression against its neighbor.
The Trump Administration is doubling down on all of President Obama's mistakes. Siding with al-Qaeda in Yemen on the false notion that it is fighting a proxy war against Iran.
The neocons are running circles around the new US President. Deal-maker? On foreign affairs, he's more like a vulnerable rube walking into a used car lot populated by shark car salesmen.
By the way, the Pentagon just finished investigating the Pentagon over the disastrous Yemen raid – where scores of civilians were gunned down by the US military in cold blood but they missed the claimed target. It may shock you, but the Pentagon found that the Pentagon had done nothing wrong. Investigation complete!
Daniel McAdams is director of the The Ron Paul Institute for Peace & Prosperity. Reprinted from The Ron Paul Institute for Peace & Prosperity.


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Kick News for iPhone
Kick News is a football (soccer) news reader for the iPhone. We gather the latest stories from from a large number of sources and using our unique algorithm, you can see what stories are currently popular.
Just like this website (http://www.kicknews.com) you can view the latest football news from all over the web, but in a dedicated iPhone app, fully customised for your club, making it much easier than ever before to access the news that matters, wherever you are.
Clicking on any story in the list, you can view the story directly from the app with the built in web-browser, making it easy to return to the story index at any time.
We also include the latest scores and league table.
We have dedicated club editions on the App store as well, which don't have any adverts in and include live Goal Alerts.View on Apple's website and download for FREE via iTunes.
Kick News for Android
We've also worked hard on our Android version and we're very pleased with it. Download it from the Android Market. If you like it, please give it a review. We really appricate your support.View on the Android Market and download for free.


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Posted by Editoress on 04/9/01
Lance & USPS Cleared
Lance Armstrong and his USPS teammates received news today that the results of urine tests taken during the 2000 TDF have all come back clear of performance enhancing drugs. Armstrong maintained that nothing would be found and indeed he has been proven correct.
Armstrong will compete in the Circuit de la Sarthe, April 10-13 in France.
Intersports Welcomes Brit. Caroline Alexander to Team!
Courtesy Intersports
The Intersports Women's cycling team, recent winners of the Solano Cycling Classic are pleased to welcome Mountain bike superstar, Caroline Alexander to the fold for 2001. Caroline is a former Olympian (Atlanta and Sydney) and World Cup winner. Hot on the heels of a stellar ride in Napa and overall victory at the Sea Otter Classic, Alexander will sport the Intersports colours for her appearances on the road in 2001.
Starting with the Tour of Willamette April 10-16 and followed by the Montreal World Cup and HP Women's Challenge, Alexander will lend a strong hand on the hills to Intersports already proven flat land ability. Expect to see Intersports climber Sandy Espeseth alongside Alexander as the road steepens in 2001.
OBC Life Member Passes Away
Roy Fowler 1916 - 2001
It is with great sadness that we report the death of Ottawa Bicycle Club member #.1, Roy Fowler. Roy was made a life member of the club in the early 1980's in recognition of his service to the Club. He first served on the Board in 1973 as Touring Director, and since had been Social Director, twice Newsletter Editor, three times Vice-President, and twice President. He was ably supported by wife Mary and daughter Sue both of whom also served in official capacities during the same period as Roy did. Roy died at his home in Ottawa yesterday. He was 84 years old.
Our deepest regrets are extended to members of Roy's family. Our thoughts are with them.
Avery Burdett
|Return to Canadian Cyclist homepage | Back to Top


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congrads on being a superstar member!!
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Just for you! Monetizing WordPress over Blogger
This is a fantastic question! I definitely want to say first off that WordPress is a better choice for monetizing your blog - but it will take me a few minutes or so to compile my reasons why (which there are several, in my professional experience). Give me an hour to write something up (as this is definitely beneficial for everyone).
Sure! What questions do you have =)


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Astronomy's next big discovery is probably hiding in piles of old data
The ability to gather more information means we'll spend more time sifting through it.
Earlier this year, astronomers stumbled upon a fascinating finding: Thousands of black holes likely exist near the center of our galaxy. The X-ray images that enabled this discovery weren't from some state-of-the-art new telescope. Nor were they even recently taken—some of the data was collected nearly 20 years ago. No, the researchers discovered the black holes by digging through old, long-archived data. Discoveries like this will only become more common, as the era of "big data" changes how science is done. Astronomers are gathering an exponentially greater amount of data every day—so much that it will take years to uncover all the hidden signals buried in the archives. The evolution of astronomy Sixty years ago, the typical astronomer worked largely alone or in a small team. They likely had access to a respectably large ground-based optical telescope at their home institution.
Their observations were largely confined to optical wavelengths—more or less what the eye can see. That meant they missed signals from a host of astrophysical sources, which can emit non-visible radiation from very low-frequency radio all the way up to high-energy gamma rays. For the most part, if you wanted to do astronomy, you had to be an academic or eccentric rich person with access to a good telescope.
Old data was stored in the form of photographic plates or published catalogs. But accessing archives from other observatories could be difficult—and it was virtually impossible for amateur astronomers.
Today, there are observatories that cover the entire electromagnetic spectrum. No longer operated by single institutions, these state-of-the-art observatories are usually launched by space agencies and are often joint efforts involving many countries.
With the coming of the digital age, almost all data are publicly available shortly after they are obtained. This makes astronomy very democratic—anyone who wants to can reanalyze almost any data set that makes the news. (You too can look at the Chandra data that led to the discovery of thousands of black holes!)
These observatories generate a staggering amount of data. For example, the Hubble Space Telescope, operating since 1990, has made over 1.3 million observations and transmits around 20 GB of raw data every week, which is impressive for a telescope first designed in the 1970s. The Atacama Large Millimeter Array in Chile now anticipates adding 2 TB of data to its archives every day.
Data firehose
The archives of astronomical data are already impressively large. But things are about to explode.
Each generation of observatories are usually at least 10 times more sensitive than the previous, either because of improved technology or because the mission is simply larger. Depending on how long a new mission runs, it can detect hundreds of times more astronomical sources than previous missions at that wavelength.
For example, compare the early EGRET gamma ray observatory, which flew in the 1990s, to NASA's flagship mission Fermi, which turns 10 this year. EGRET detected only about 190 gamma ray sources in the sky. Fermi has seen over 5,000.
The Large Synoptic Survey Telescope, an optical telescope currently under construction in Chile, will image the entire sky every few nights. It will be so sensitive that it will generate 10 million alerts per night on new or transient sources, leading to a catalog of over 15 petabytes after 10 years.
The Square Kilometre Array, when completed in 2020, will be the most sensitive telescope in the world, capable of detecting airport radar stations of alien civilizations up to 50 light-years away. In just one year of activity, it will generate more data than the entire internet.
These ambitious projects will test scientists' ability to handle data. Images will need to be automatically processed—meaning that the data will need to be reduced down to a manageable size or transformed into a finished product. The new observatories are pushing the envelope of computational power, requiring facilities capable of processing hundreds of terabytes per day.
The resulting archives—all publicly searchable—will contain 1 million times more information that what can be stored on your typical 1 TB backup disk.
Unlocking new science
The data deluge will make astronomy become a more collaborative and open science than ever before. Thanks to internet archives, robust learning communities and new outreach initiatives, citizens can now participate in science. For example, with the computer program Einstein@Home, anyone can use their computer's idle time to help search for gravitational waves from colliding black holes.
It's an exciting time for scientists, too. Astronomers like myself often study physical phenomena on timescales so wildly beyond the typical human lifetime that watching them in real-time just isn't going to happen. Events like a typical galaxy merger—which is exactly what it sounds like—can take hundreds of millions of years. All we can capture is a snapshot, like a single still frame from a video of a car accident.
However, there are some phenomena that occur on shorter timescales, taking just a few decades, years or even seconds. That's how scientists discovered those thousands of black holes in the new study. It's also how they recently realized that the X-ray emission from the center of a nearby dwarf galaxy has been fading since first detected in the 1990s. These new discoveries suggest that more will be found in archival data spanning decades.
In my own work, I use Hubble archives to make movies of "jets," high-speed plasma ejected in beams from black holes. I used over 400 raw images spanning 13 years to make a movie of the jet in nearby galaxy M87. That movie showed, for the first time, the twisting motions of the plasma, suggesting that the jet has a helical structure.
This kind of work was only possible because other observers, for other purposes, just happened to capture images of the source I was interested in, back when I was in kindergarten. As astronomical images become larger, higher resolution and ever more sensitive, this kind of research will become the norm.
Eileen Meyer is an Assistant Professor of Physics at the University of Maryland, Baltimore County. This article was originally featured on The Conversation.


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| Alcohol - Related problems as an obstacle to the development of human capital
Issues and Policy Options
James A. Cercone
The World Bank
Washington, D.C.
Copyright (D 1994 The International Bank for Reconstruction and Development/THE WORLD BANK 1818 H Street, N.W. Washington, D.C. 20433, U.S.A.
All rights reserved
Manufactured in the United States of America
First printing January 1994
Technical Papers are published to communicate the results of the Bank's work to the development community with the least possible delay. The typescript of this paper therefore has not been prepared in accordance with the procedures appropriate to formal printed texts, and the World Bank accepts no responsibility for errors. Some sources cited in this paper may be informal documents that are not readily available.
The findings, interpretations, and conclusions expressed in this paper are entirely those of the author(s) and should not be attributed in any manner to the World Bank, to its affiliated organizations, or to members of its Board of Executive Directors or the countries they represent. The World Bank does not guarantee the accuracy of the data included in this publication and accepts no responsibility whatsoever for any consequence of their use. Any maps that accompany the text have been prepared solely for the convenience of readers; the designations and presentation of material in them do not imply the expression of any opinion whatsoever on the part of the World Bank, its affiliates, or its Board or member countries concerning the legal status of any country, territory, city, or area or of the authorities thereof or concerning the delimitation of its boundaries or its national affiliation.
The material in this publication is copyrighted. Requests for permission to reproduce portions of it should be sent to the Office of the Publisher at the address shown in the copyright notice above. The World Bank encourages dissemination of its work and will normally give permission promptly and, when the reproduction is for noncommercial purposes, without asking a fee. Permission to copy portions for classroom use is granted through the Copyright Clearance Center, Inc., Suite 910, 222 Rosewood Drive, Danvers, Massachusetts 01923, U.S.A.
The complete backlist of publications from the World Bank is shown in the annual Index of Publications, which contains an alphabetical title list (with full ordering information) and indexes of subjects, authors, and countries and regions. The latest edition is available free of charge from the Distribution Unit, Office of the Publisher, The World Bank, 1818 H Street, N.W., Washington, D.C. 20433, U.S.A., or from Publications, The World Bank, 66, avenue d'léna, 75116 Paris, France.
James A. Cercone is a health economist who was working as a consultant to the Population, Health and Nutrition Department of the World Bank when this report was written.
Library of Congress Cataloging-in-Publication Data
Cercone, James A., 1968
Alcohol-related problems as an obstacle to the development of human capital: issues and policy options / James A. Cercone.
p. cm. — (World Bank technical paper; no. 219)
Includes bibliographical references.
I. Alcoholism. 2. Alcoholism—Economic aspects. 1. Title.
II. Series.
362.29'2—dc20 93-6168
No. 251 Sharma, Rietbergen, Heimo, and Pa tel. A Strategy for the Forest Sector in Sub-Saharan Africa
No. 252 The World Bank/FAO/UNIDO/lndustry Fertilizer Working Group, World and Regional Supply and Demand Balances for Nitrogen, Phosphate, and Potash, 1992/93-1998/99
No. 253 Jensen and Malter, Protected Agriculture: A Global Review
No. 254 Frischtak, Governance Capacity and Economic Reform in Developing Countries
No. 255 Mohan, editor, Bibliography of Publications: Technical Department, Africa Region, July 1987 to April 1994
No. 256 Campbell, Design and Operation of Smallholder Irrigation in South Asia
No. 258 De Geyndt, Managing the Quality of Health Care in Developing Countries
No. 259 Chaudry, Reid, and Malik, editors, Civil Service Reform in Latin America and the Caribbean: Proceedings of a Conference
No. 260 Humphrey, Payment Systems: Principles, Practice, and Improvements
No. 261 Lynch, Provision for Children with Special Educational Needs in the Asia Region
No. 262 Lee and Bobadilla, Health Statistics for the Americas
No. 263 Le Moigne, Subramanian, Xie, and Giltner, editors, A Guide to the Formulation of Water Resources Strategy
No. 264 Miller and Jones, Organic and Compost-Based Growing Media for Tree Seedling Nurseries
No. 265 Viswanath, Building Partnerships for Poverty Reduction: The Participatory Project Planning Approach of the Women's Enterprise Management Training Outreach Program (WEMTOP)
No. 266 Hill and Bender, Developing the Regulatory Environment for Competitive Agricultural Markets
No. 267 Valdés and Schaeffer, Surveillance of Agricultural Prices and Trade: A Handbook for the Dominican Republic
No. 268 Valdés and Schaeffer, Surveillance of Agricultural Prices and Trade: A Handbook for Colombia
No. 269 Scheierling, Overcoming Agricultural Pollution of Water: The Challenge of Integrating Agricultural and Environmental Policies in the European Union
No. 270 Banerjee, Rehabilitation of Degraded Forests in Asia
No. 271 Ahmed, Technological Development and Pollution Abatement: A Study of How Enterprises Are Finding Alternatives to Chlorofluorocarbons
No. 272 Greaney and Kellaghan, Equity Issues in Public Examinations in Developing Countries
No. 273 Grimshaw and Helfer, editors, Vetiver Grass for Soil and Water Conservation, Land Rehabilitation, and Embankment Stabilization: A Collection of Papers and Newsletters Compiled by the Vetiver Network
No. 274 Govindaraj, Murray, and Chellaraj, Health Expenditures in Latin America
No. 275 Heggie, Management and Financing of Roads: An Agenda for Reform
No. 276 Johnson, Quality Review Schemes for Auditors: Their Potential for Sub-Saharan Africa
No. 277 Convery, Applying Environmental Economics in Africa
No. 278 Wijetilleke and Karunaratne, Air Quality Management: Considerations for Developing Countries
No. 279 Anderson and Ahmed, The Case for Solar Energy Investments
No. 280 Rowat, Malik, and Dakolias, Judicial Reform in Latin America and the Caribbean: Proceedings of a World Bank Conference
No. 281 Shen and Contreras-Hermosilla, Environmental and Economic Issues in Forestry: Selected Case Studies in Asia
No. 282 Kim and Benton, Cost-Benefit Analysis of the Onchocerciasis Control Program (OCP)
No. 283 Jacobsen, Scobie and Duncan, Statutory Intervention in Agricultural Marketing: A New Zealand Perspective
No. 284 Valdés and Schaeffer in collaboration with Roldos and Chiara, Surveillance of Agricultural Price and Trade Policies: A Handbook for Uruguay
No. 285 Brehrn and Castro, The Market for Water Rights in Chile: Major Issues
No. 286 Tavoulareas and Charpentier, Clean Coal Technologies for Developing Countries
No. 287 Giliham, Bell, Arin, Matthews, Rumeur, and Hearn, Cotton Production Prospects for tire Next Decade
No. 288 Biggs, Shaw, and Srivastiva, Technological Capabilities and Learning in African Enterprises
No. 289 Dinar, Seidl, Olem, Jorden, Duda, and Johnson, Restoring and Protecting the World's Lakes and Reservoirs
No. 290 Weijenberg, Dagg, Kampen Kalunda, Mailu, Ketema, Navarro, and Abdi Noor, Strengthening National Agricultual Research Systems in Eastern and Central Africa: A Framework for Action
No. 291 Valdés and Schaeffer in collaboration with Errazuriz and Francisco, SurveilIance of Agricultural Price and Trade Policies: A Handbook for Chile
No. 292 Gorriz, Subramanian, and Simas, Irrigation Management Transfer in Mexico: Process and Progress
No. 293 Preker and Feachem, Market Mechanisms and the Health Sector in Central and Eastern Europe
No. 294 Valdés and Schaeffer in collaboration with Sturzenegger and Bebczuk, Surveillance of Agricultural Price and Trade Policies: A Handbook for Argentina
No. 295 Pohl, Jedrzejczak, and Anderson, Creating Capital Markets in Central and Eastern Europe
No. 296 Stassen, Small-Scale Biomass Gasifiers for Heat and Power: A Global Review
No. 297 Bulatao, Key Indicators for Family Planning Projects
No. 298 Odaga and Heneveld, Girls and Schools in Sub-Saharan Africa: From Analysis to Action
No. 299 Tamale, Jones, and Pswarayi-Riddihough, Technologies Related to Participatory Forestry in Tropical and Subtropical Countries
No. 300 Oram and de Haan, Technologies for Rainfed Agriculture in Mediterranean Climates: A Review of World Bank Experiences
No. 301 Edited by Mohan, Bibliography of Publications: Technical Department, Africa Region, July 1987 to April 1995
No. 302 Baldry, Calamari, and Yaméogo, Environmental Impact Assessment of Settlement and Development in the Upper Léraba Basin
No. 303 Heneveld and Craig, Schools Count: World Bank Project Designs and the Quality of Primary Education in Sub-Saharan Africa
No. 304 Foley, Photovoltaic Applications in Rural Areas of the Developing World
No. 305 Johnson, Education and Training of Accountants in Sub-Saharan Anglophone Africa
No. 306 Muir and Saba, Improving State Enterprise Performance: The Role of Internal and External Incentives
No. 307 Narayan, Toward Participatory Research
No. 308 Adamson and others, Energy Use, Air Pollution, and Environmental Policy in Krakow: Can Economic Incentives Really Help?
No. 309 The World Bank/FOA/UNIDO/lndustry Fertilizer Working Group, World and Regional Supply and Demand Balances for Nitrogen, Phosphate, and Potash, 1993/94-1999/2000
No. 310 Edited by Elder and Cooley, Sustainable Settlement and Development of the Onchocerciasis Control Programme Area: Proceedings of a Ministerial Meeting.
No. 311 Webster, Riopelle and Chidzero, World Bank Lending for Small Enterprises 1989-1993
No. 312 Benoit, Project Finance at the World Bank: An Overview of Policies and Instruments
No. 313 Kapur, Airport Infrastructure. The Emerging Role of the Private Sector
No. 314 Valdés, Schaefferin collaboration with Ramos, Surveillance of Agricultural Price and Trade Policies: A Handbook for Ecuador
No. 316 Schware and Kimberley, Information Technology and National Trade Facilitation: Making the Most of Global Trade
No. 317 Schware and Kimberley, Information Technology and National Trade Facilitation. Guide to Best Practice
No. 318 Taylor, Boukambou, Dahniya, Ouayogode, Ayling, Abdi Noor, and Toure, Strengthening National Agricultural Research Systems in the Humid and Sub-humid Zones of West and Central Africa: A Framework for Action
No. 320 Srivastava, Lambert and Vietmeyer, Medicinal Plants: An Expanding Role in Development
No. 321 Srivastava, Smith, and Forno, Biodiversity and Agriculture: Implications for Conservation and Development
No. 322 Charles M. Peters, The Ecology and Management of Non-Timber Forest Resources
No. 323 Edited by Dominique Pannier, Corporate Governance of Public Enterprises in Transitional Economies
No. 324 Cabraal, Cosgrove-Davies, and Schaeffer, Best Practices for Photovoltaic Household Electrification Programs
No. 325 Bacon, Besant-Jones, and Heidarian, Estimating Construction Costs and Schedules: Experience with Power Generation Projects in Developing Countries


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Juvederm™ is an injectable dermal gel filler used to correct facial folds and wrinkles. It is composed of hyaluronic acid, a naturally occurring substance found in the body, and is safe and effective in patients of all skin types. Juvederm™ is injected into the folds and wrinkles of the patient to create volume and fullness, and also to improve the moisture content of the skin.
Juvederm™ is an ideal non-surgical cosmetic procedure as the gel flows easily into the skin, creating a smooth and natural look and feel. Juvederm™ works best for moderate wrinkles in the cheeks and moderately severe nasolabial folds (the deep folds running from the side of the nose to the corner of the mouth). Juvederm™ is also great for defining and plumping the lips.
The injection process approximately 15 minutes, and the results are immediate. Recovery time is quick, and side effects are generally mild. There may be some temporary redness, discomfort, swelling or bumps, which will alleviate in a few days.


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Saturday - June 29th
9:30 am to 1:00 pm
Victory Park (next to the Haggin Museum)
The 3rd Annual DeltaFusion is a celebration of the diverse natural and cultural heritage of Stockton and the San Joaquin Delta Region. Using giant puppets, masks, music, and pageantry, DeltaFusion tells the story of how these cultures were drawn to settle in our area and thrive there today. This year's theme is: "The Strength of Many."
In addition to the parade and pageant, there will be food, craft, and informational booths and vendors as well as live performances from a variety of dance and musical groups representing the cultural diversity found within San Joaquin Delta Region.


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- Mobile Teeth Roll Crusher
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Scheduled for 27 May 2012, Group Lotus brand ambassador Jean Alesi will make his return to competitive racing flying the flag for Group Lotus at the world's biggest motorsport race – the 96th Indy 500.
Despite his considerable experience, Jean has never before taken on competitive oval racing. Following a 12 year stint in F1 from 1989 to 2001, Alesi moved onto DTM racing and then last year made his most recent competitive race appearance in the Le Mans Series. In January 2011 he joined Group Lotus as a brand ambassador and development consultant on the F1 customer race car, the T125. Although never straying far from the race track, the Indy 500 and oval racing represent completely new challenges for Jean.
Commenting on the announcement Jean Alesi said: "I'm thrilled that Lotus has given me the opportunity to compete in such a world famous race. It's going to be a very special experience for me but I also know that I have a lot of hard work ahead. I'm very focused on the task I'm facing – I'm taking my training very seriously, I have some amazing support on this front from a 'comeback' expert and of course I will be testing extensively. I'm really excited about the race."
Jean's development role with Group Lotus will stand him in good stead as he prepares for his new challenge as he will be competing in a Lotus powered by the new Lotus IndyCar engine. Development of the 2.2l twin turbo V6 is going to schedule with the first engine fire up set for mid October and track testing planned December.
Group Lotus Director of Corporate Operations Gino Rosato said: "IndyCar racing represents a really important element of our overall motorsport program. The Indy 500 is the highlight of the race calendar, the atmosphere is always incredible and having Jean racing for us there will make it extra special."