TRS lock hardening question

[conquerordie]

Had to take a break from building the last couple weeks. Now I'm trying I finish a TRS lock kit. I've done all the springs, all work great. Now on to be tumbler and sear. What temps and for how long should these be tempered? The TRS website has nothing on these parts except that it's necessary to harden them. Any guidance would be great. Thanks,
Greg

[conquerordie]

Oh yeah.....the parts are made of 4140.
Greg

[jerrywh]

 4140 is a low carbon steel and will require case hardening and tempering. I don't think you need to case harden the lock plate but I would do the internals. It seems very strange that they would cast flintlock parts out of 4140.
  It could be that it was just what the foundry happened to be using at the time. Nothing wrong with it. It just seems like overkill. It is very tough and good for hammers.
  1550° in a charcoal pack for 1.5 hours and quench in room temp water. Temper at 350°to 400° for 1 hour minimum. Kitchen oven works for that.

[conquerordie]

Did this yesterday afternoon and the parts seem to have come out great. Thanks a million!
Greg