C$_{2}$ C$_{1}$ D Grip range 100°  ±  1° 100°  ±  2° 0.028 0.037 0.046 0.046 B REF 0.028 0.037 0.046 0.046 1/8 (–4) 5/32 (–5) 3/16 (–6) 7/32 (–7) C1 DIA 0.195 0.189 0.247 0.242 0.302 0.297 0.328 0.323 C2 DIA 0.195 0.189 0.247 0.242 0.302 0.297 0.328 0.323 D DIA 0.132 0.129 0.162 0.159 0.195 0.191 0.227 0.224 Rivet Diameter A REF CSR 90433 A (ref) for manufactured head B (ref) for shop-formed head 2,500 2,700 3,000 3,750 1/8" (–4) 5/32" (–5) 3/16" (–6) 7/32" (–7) Hollow End E-Z Buck® Nominal Diameter Upset Load (Lb) + 200 Lb 839B10-4 839B10-5 839B10-6 839B10-7 1/8" 5/32" 3/16" 7/32" 839B1-4 839B1-5 839B1-6 839B1-7 Rivet Diameter 1/4" Diameter Mount 3/16" Diameter Mount Cherry Flaring Snap Die Part Numbers Flushness +0.005 −0.000 Flushness +0.015 −0.000 Head dimple Squeezer yoke or riveting machine Cherry flaring snap die Hollow End E-Z Buck ® Composite material Cherry snap die (optional) (839B3 = 3/16" shank size) (839B13 = 1/4" shank size) Note: 1 die fits all fastener diameters. Manufactured head Shop formed head Figure 7-82.  Cherry’s E-Z Buck hollow rivet. Machining Processes and Equipment Drilling Equipment 7-49 Air-driven tools are used for drilling holes in composite  materials. Drill motors with free speed of up to 20,000 rpm  are used. A general rule for drilling composites is to use high  speed and a low feed rate (pressure). Drilling equipment  with a power feed control produces better hole quality than  drill motors without power feed control. Drill guides are  recommended, especially for thicker laminates.  Do not use standard twist drill bits for drilling composite  structures. Standard high-speed steel is unacceptable, because  it dulls immediately, generates excessive heat, and causes ply  delamination, fiber tear-out, and unacceptable hole quality. Drill bits used for carbon fiber and fiberglass are made from  diamond-coated material or solid carbide because the fibers  Hole drilling in composite materials is different from drilling  holes in metal aircraft structures. Different types of drill bits,  higher speeds, and lower feeds are required to drill precision  holes. Structures made from carbon fiber and epoxy resin  are very hard and abrasive, requiring special flat flute drills  or similar four-flute drills. Aramid fiber (Kevlar$^{®}$)/epoxy  composites are not as hard as carbon but are difficult to  drill unless special cutters are used because the fibers tend  to fray or shred unless they are cut clean while embedded  in the epoxy. Special drill bits with clothes pin points and  fish-tail points have been developed that slice the fibers prior  to pulling them out of the drilled hole. If the Kevlar$^{®}$/epoxy  part is sandwiched between two metal parts, standard twist  drills can be used.