I don't want off the part to surface
grind if i don't have to. I'm wondering if these is some epoxy or ? I
could use to fill this very small and shallow scratch. As I said a
crush washer is going over this surface.
I've tried stoning and its not going away. Any ideas?

Looks like you need Permatex PermaShield. According to their specs it
resists gas and can be put into service immediately.


BTW... you mentioned that it doesn't "fill cracks". You're NOT FILLING
CRACKS... just scratches!

Lloyd