Tap
A tap is a tool that can be used when building screw threads. A form of cutting tool, a tap forms the female portion of the mating pair used to later combine parts. When using a tap to cut the threads on a screw, the process is called tapping. Taps are difficult to measure given the off number of flutes. Due to this, a v-anvil micrometer is the best device to use when taking measurements of a tap.