How thin before heat treat?

H

h2ostx

Joined
Sep 3, 2004
Messages
154
I was grinding a blade on a small drop point hunter in S30V, getting it ready to send for heat treat. But I'm not sure if I maybe got it a little too thin at the tip.

The edge is .028" at the tip tapering to .040" thickness at the plunge, is it too thin?? :confused: It started out as 1/8" stock size S30V. Will this warp too much if I try to have it HT'ed?

Thanks for all the info guys.

Kelly
 
When you grind a knife you should have at least 70 thousands. whoever is going to heat treated your knife will probably send it back, if he knows anything about heat treating blades. You may want to call that person and let him know the thickness. If I was you, I would pitch that one and start a new one and leave at least 70 thousand thick. Hope this was of help to you. God bless and have a great knife day in the shop. Note: Grind the shape and drill all your holes and stamp your name. Then send out for heat treat. And when you get it back then grind it out to that.

Barkes :thumbdn:
http://my.hsonline.net/wizard
 
i shoot fro a dime thickness(.055)
i also do my own heat treatign and leave extra at the spine
also i foil wrap all my blades(cuts down on decarb) as i mostly do cpm154 now a days
 
.028 would be no problem at all here. We do get a little growly at sharpened edges. The question is how fine it is finished now and whether you will have enough after heat treat to finish it to your desired finish.

If this is to be a knife for splitting the pelvis on elk and moose, you are probably too thin. If it is a fine utility or kitchen knife - or if it is close to finish, it should be fine.

Heat treat is cheap. Get it done and if there's not enough at the tip then just regrind the hardened blade (slow and cool) to a smaller blade. I've had bowies that wound up as stainless toothpicks - almost. ;)

Rob!
 
I try for .040 on stainless. As Rob said, it is the finish prior to HT that is more important. If you will have to sand off 80 grit marks, you don't have enough edge at .028. If the finish is a nice smooth 400 or finer (with no "I'll fix that after HT" areas) then you have no problem. The stainless HT done by most professionals comes back looking exactly like it left,so the more done before HT the better.
Stacy
 
Thanks guys,

I am at 320 grit now, so I am going to give it a try. My plan is to use this as a small skinning/utility kitchen knife, so I don't see it being used for cutting thru large joints.
I was planning to have the finished edge be about .020" or .015" thick. Mainly because of the info I read in some of the other post about edge holding of
S30V and how too thick of blades can be a problem. I just wasn't planning to be there before HT.:rolleyes:

Thanks for the information.

Kelly
 
I have never had a problem with totaly finishing them all the way out before HT mine is 15thousands if lucky and I have never had a problem
 
I'm new to this and learning. But I just scraped a blade that i ground
to thin .043. I intentionally snapped it, measured it after it put a real
bad bow in part of the blade. It was a experienced ht guy who told me
before we started what was going to happen. It was just cheap 1095
I bought to learn how to grind on. So not out alot of $$in steel but still
how some time in it. I've been told to stay at .065 to .070 like one of
the other guys posted. Thats my intention from now on.(hunting knives)
 
AMCJAVELIN401

Good distinction. The original post was about an air quenching steel which will be treated in a computer controlled furnace with some means of excluding Oxygen and will probably be plate quenched.

If you heat treating in a forge, there will be uneven temperatures (relative to computer controlled) and exposure to oxygen at high temperatures and using the oil quench there will also be more cleanup grinding to do. Leaving extra meat for after hardening grinding is good advice for those ones.

Disclaimer

I don't have a forge, but I do HT oil quench steels in the oven.

Rob!
 
Years ago I contacted Paul Bos to do my HT, and asked him that question. He told me to fininish if I liked as it would save time and work later.I now do my own and take them as close as I dare, and still leave cleanup room. No problems.
 
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