Heat treating a file knife?

[Southern14]

Well I recently made my first home made file knife. Before I attach the handle would I need to heat treat and temper this knife? I only put it on a grinder (dipping it in water after ever few passes so the blade wouldn't get too hot). The blade is 4 inches, including tang 7 1/2inches. It is very narrow from back to edge it's 1/2 and inch and thickness is about 1-2/16 of an inch. With those dimensions, if it needs it, what would the proper heat treating/tempering be? Only if it needs it. Thanks in advance.

 

[Skeptikos]

Assuming it is not a case hardened file and that you did not overheat it, the metal should be very hard now. If you want the easiest alternative, I would suggest only tempering it, in case it is too brittle. Some guys do it and are happy with the results. If you are a control freak you can go through a triple normalization+hardening+double tempering process. You should move this post to the General Knife Maker's Discussion/Shop Talk forum to ask for details.

 

[Southern14]

I'll leave it as is until I hone the edge properly. If it doesn't hold an edge well (if the metal is too hard it will just chip and get rough) then ill temper it. Thank you for the help.

 

[1066vik]

If it's still full hardness, another file should skate off the steel -- an easy test.
If it is that hard, an easy temper is to heat the clean piece of steel in the oven for 2 hours at 400-425F, then cool it down in a bucket full of room temp water.
Once it's cool enough to hold with a bare hand, put it back in the 400-425F oven for another 2 hours, then dunk again.