90 degree flex test

Joined
May 22, 2008
Messages
603
Well I got a knife to do a flex test. The knife is 1084 1/8" nessmuk.
The blade was edge quench, torched on the back w/ edge in oil 3 times and then oven tempered for the edge 3 time at 370 degrees.
In the pic you can see some flex in the handle too. Should I put a handle on and try the flex again.
What do you think
Thanks for looking
Eric Knight
 

Nathan the Machinist

KnifeMaker / Machinist / Evil Genius
Moderator
Knifemaker / Craftsman / Service Provider
Joined
Feb 13, 2007
Messages
13,982
it didn't come back to straight. but it was about 80% of straight.
Eric Knight

Thats good.

Well, normally the knife has a handle on it and all of the flex is in the blade, so this is "cheating" a little bit. But, normally the blade is longer than that, spreading the bend over a larger area, reducing the severity of the test. It appears you obtained the HT you were after. The trick is obtaining that from a forged blade, that has been subjected to the forging temps and then corrected, plus the cutting test (because any soft blade will pass the bend test).

Go hack a 2X4 in half with it and see if it still shaves hair with the part of the edge used to cut the 2X4. They don't even look at a flex test until that has been achieved.

Still, that looks like quite an accomplishment, very nice.
 
Joined
May 22, 2008
Messages
603
sounds good thanks for the info. I will go hit so 2x4 and post the results
I also have a 52100 forged blade this is going to get the test next when it gets heat treated and tempered
Eric Knight
 
Top