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 ...

Collapsible taps have interchangeable tap heads and a common body, and will tap virtually any thread form with the appropriate chaser. Styles include: Model ALTs for straight-thread tapping, Model LLs ...

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 ...