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Trust
11-07-2010, 11:19 AM
So I've been working on my 1st knife and have the edge to 1/16" thickness and was wondering if I needed to stop there and send it out for HT now or go ahead and bring the final edge a little closer to finish. Please keep in mind all my work for the bevels and edge is being done with files.

rjarois
11-07-2010, 11:49 AM
i am rather new to the knife building....but on my first knife i took down to about .020 and rounded it a bit with some 320 grit. the heat treat was commercially done, and the blade is D2 at 59r/c. everything was good. randy.

Trust
11-07-2010, 12:08 PM
Thanks, working with 440C and I'll take it down some more before sending it off.

Justin King
11-07-2010, 01:44 PM
With air hardening or stainless steels you can usually go within .010-.020 of final thickness before HT. With oil hardening alloys you generally want to leave a little more meat at the edge. If it were oil hardening I would say stop before you get much thinner, but with 440 you should be able to go pretty close.

SBuzek
11-07-2010, 03:20 PM
I take 440-C to .015-.020 pre H/T.Works well.
Stan

Trust
11-07-2010, 04:18 PM
Thanks for all the information, busting the files back out to thin the edge out some.

rjarois
11-07-2010, 05:58 PM
also round any sharp corners on the blade, including the holes.....any sharp corner or edge, as sharp corners in any metal getting a HT process will produce stress risers, and may initialize a crack. randy.

Trust
11-07-2010, 07:17 PM
also round any sharp corners on the blade, including the holes.....any sharp corner or edge, as sharp corners in any metal getting a HT process will produce stress risers, and may initialize a crack. randy.

Much appreciated! This is something I was not aware of or had even thought about.

rjarois
11-08-2010, 02:56 AM
no problem trust.....even though I'm new to knife making, i have been in tool and die for over 30 years, and have lots of experence with heat treat, lols. good luck with your build. randy.

Todd Robbins
11-10-2010, 10:15 AM
On my air hardening steels, I take the edge to finished thickness and hand sand to 220 grit before sending it out. When it comes back, I clean off the discoloration from heat treating with 220 grit and go from there. I don't do any grinding after heat treat on most of my air hardening steels, with the exception being some kitchen knives and filet knives I've made of 1/16" stock. I send them out after they're profiled but without the bevels ground.

Todd

Fellhoelter
11-10-2010, 11:40 PM
In 440C, I finish the blade pre-ht.
Then all I have to do after HT is clean her up.