Knurling is the mechanical process that creates a rough textured pattern on a surface by pressing a textured tool against a rotating surface.
Knurling provides a way to create grips without additional components. Shapes are primarily cylindrical surfaces. Usually diamond or parallel line patterns and used.
A few examples of uses include tool handles, decorative stripes, grips for threaded adjusting devices and thumbscrews. The process is usually done on ductile metals.
Cost reduction options are primarily reduction of the diameter and length of the knurled surface.