The masonry bit shown here is a variation of the twist drill bit. Straight fluted drill bits do not have a helical twist like twist drill bits do. The Morse taper twist drill bits pictured right are used in metalworking. "Long series" drill bits are unusually long twist drill bits. The twist drill bit is the type produced in largest quantity today. Twist drill bits are available in the widest choice of tooling materials. Conventional twist drill bits tend to wander when presented to a flat workpiece. Traditional twist drill bits may tend to wander when started on an unprepared surface. Twist drill bits range in diameter from and can be as long as . The Rail Twist Drill or Rail Drill Bits are the types of Spiral Drill Bits. In the early 1980s, Union Twist Drill closed, and has largely been empty since. It can use twist drill bits, annular cutters, milling cutters, and other rotary cutters.