This is a post by Aaron Shaw on PTC site.
Pick up an old pliers, a metal dumbbell, or a dart from your dartboard, and you’ll notice their handles have a similar texture. The process that creates the crisscross pattern cut in the metal is called knurling. It’s used on various handles, knobs, and thumbscrews where someone might need extra grip.
Tool with knurling on the surface (from Wikipedia)
How do you create knurled surfaces in the workshop? Watch the video below:
Curious about how to create that texture in a PTC Creo project? It’s all done with helical sweeps:
Why Helical Sweeps?