Final answer:
Knurling is the process of rolling a pattern onto a workpiece to improve grip, commonly found on tools like wrenches.
Step-by-step explanation:
Knurling is a machining process typically carried out on a lathe wherein a pattern of straight, angled, or crossed lines is rolled into the material. This process does not cut the material like in threading but rather deforms and displaces it, creating a rough surface that is better to grip. The knurled pattern is often found on tools, like wrenches or screwdriver handles, where a secure grip is necessary. It adds both a functional and aesthetic quality to the piece.