Taps

Standardization carried out in thread forms and threading methods rarely makes it necessary for the tool designer to design special taps. The design of special tapping fixtures is quite common, and in order to accomplish this, the tool designer must understand the construction and cutting action of taps. the same tap may act differently when used in different materials.

The size of a tapped hole depends on the tapping equipment used, alignment, speed of operation material to be tapped, size and condition of the hole, and the type of cutting fluid used.

The Metal Cutting Institute defines a tap as a cylindrical or conical thread cutting tool with one or more cutting elements having threads of a desired form on the periphery.

A tap is simply a hardened tool steel screw with lengthwise grooves called flutes milled or ground across the threads. The flutes form a series of teeth and provide chip into a hole of proper diameter, the teeth cut into the wall of the hole and remove material to form threads of the same pitch as the threads of the tap.