final edge

If I understand your question, I usually take mine down to between .020 and .030 thick if I can, depending on the thickness of the stock and the intendid use of the knife.
 
If you have already heat treated the blade, the thickness of the edge is up to you. Personally I look for about .02 or there abouts.
 
i am new here, and to knife making as well, but wouldn't the type of steel being used and the speed of quench be a factor as well? unless you already heat treated that is...
 
"but wouldn't the type of steel being used and the speed of quench be a factor as well? unless you already heat treated that is... "

Absolutely.
 
I think that this question of how far to take the edge down before quenching is a little overblown. I've had to repeat the heat treating on knives that have failed the edge test, which I do at a course edge, and have never had any warping from it. Maybe it's beginners luck but the only time that I had warping in the edge was when I over heated the steel and that edge did come out looking like a potato chip. If the blade has already been hardened and tempered then I take it to a course edge, being careful not to over heat, and then refine the edge on stones and a leather strop.

Doug
 
"I think that this question of how far to take the edge down before quenching is a little overblown."

Until you pull a blade out of the oven and it is cracked down the length because it was too thin....I have a couple I could show you.
 
Sounds like I am on the right track,I take them down to .040 to .035 befor HT then to about .025 in finishing.
 
I always refer to it as "snake edge" which can happen if the edge is very thin before ht.

I like to finish grind after HT so I typically take it to .030 to .040 before hardening on oil quenching steels and finish grind to final thickness after HT. Getting my edge thin is not a priority before heat treating.

Without getting tooooo deep into what "can" happen during hardening I'll just say it's a good idea to leave it a little thicker prior to hardening to give yourself just a little wiggle room to grind out a little warp after hardening. Also, you may find your not happy with the HT and want to re-harden for whatever reason and it's nice to have a little sacrificial meat for a light re-grind to clean things back up for the second go round. Leaviing it a little on the thick side usually allows this WITHOUT needing to change the profile of the blade.

This is a topic that falls into the "Ask 10 Makers" catagory....... and you'll get 10 different answers so my reply is what works for me while others mileage may vary :)

-Josh
 
Just ten answers? Yer an optimist.:3: I prefer to leave the edge just about the thickness of a dime prior to heat treating, just to be safe, but I have re-heat treated more than one sharp blade without any warping. They were, however cases where the choice was to throw them in the reject bin or repeat the heat treatment. A lot of people have made it sound like you can't quench a blade with a sharp edge without warping when a more accurate statement would be that you may get warping, especially if you don't watch your heat.

Doug
 
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