Tapping screws form mating threads in materials they are driven into. There are two basic types: thread forming and thread cutting. The thread-forming screw displaced material around the pilot hole so ...

Twist drills do not make accurately sized or good finish holes; a reamer of some type is often used to cut the final size and finish. A reamer will not make the original hole; it will only enlarge a ...

The strength of some internal threads is more sensitive to tap diameter than previously thought. • Cold-formed threads are no stronger than cut threads when holes are correctly sized. • Cut threads ...