A couple of good grinding surface photos I found:
Spare the Bars

Image by CarbonNYC [in SF!]
Now with magic-hour light!
Asphalt abstract

Image by Eva the Weaver
Aluminium Machining China
A couple of good grinding surface photos I found:
Spare the Bars

Image by CarbonNYC [in SF!]
Now with magic-hour light!
Asphalt abstract

Image by Eva the Weaver