system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does stainless steel always have circle scratches on the surface?
gpt
I’m gonna guess you’re referring to machining marks from milling and turning and polishing of the billet steel rather than in-service contact scratches or weld formation (coin stacks/folds). 

Basically they are the marks from the tools which formed the stainless steel into its given shape by removing excess material from the work piece (the end product). 

They are circular because either the cutting tool or the work piece rotate at high velocity to give enough energy for the cutting tip on the tool to remove fine layers of material from the work piece.