Tapping cuts internal threads into a pre-drilled hole with a tap. It produces large numbers of accurate threaded holes in a short time and is used for parts that will be assembled with screws.

Thread rolling forms threads and gear profiles by pressing the material between rolling dies. Because the shape is formed rather than cut, there is little material waste, the part is stronger, and high-precision parts can be produced in volume.

NC machining cuts metal and plastics to precise dimensions under numerical control. Tool paths are programmed, so complex shapes can be reproduced with high accuracy, making the process suitable for high-mix, low-volume production.