Remington 511 sear

[Highpower]

Call Numrich and ask them what material the new part is made from. I imagine it is most likely mild steel like the original and not a medium or high carbon steel. If you have to take off an eighth of an inch you are definitely going to need to case harden the sear surface afterward if the new part is a low carbon (mild) steel. The case isn't that deep even if it was hardened previously.