bending after tempering with a vice...will it "hurt" the blade?

C

clockworkfish

Joined
Dec 1, 2010
Messages
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Hey so i did my whole heat treating process for 1080+ and then started to file down the sides and then i realized that the blade was warped. So i went over to my scrap wood bin, took out a few small wooden blocks and used two on one side of the blade and on the other side there was one block inbetween where the first 2 blocks were

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So it looked like the little diagram above, then i tightened it and the blade flexed a bunch and then eventually got into the right position.

What im wondering is, did this process damage the blade at all? as in further down the road will this make it more fragile to have had that cold flex in it?
 
oh and also i was suprised that i was able to make the blade flex about 45 degrees before if moved over in its relaxed state
 
What was your heat treating procedure? I would think the blade should have snapped if it was properly hardened.
 
Heated to 1560 quenched in warm canola tempered at 425 for 2 sessions of 2hours each. Blades came out a little on the people side so mighty have been a higher temp for the temper possibly at 500ish which should put then at 57-55rc according to the htt chart for 1080+ on aks
 
clockworkfish said:
Heated to 1560 quenched in warm canola tempered at 425 for 2 sessions of 2hours each. Blades came out a little on the people side so mighty have been a higher temp for the temper possibly at 500ish which should put then at 57-55rc according to the htt chart for 1080+ on aks
Click to expand...

Oh and let the blades come to temp with the kiln, and once they reached 1560 then have them a 5 min soak
 
The color coming out of an oven temper isn't a reliable indicator of temperature. What was the thickness of the steel?
 
I've heard that the thinner the steel the farther it will bend before taking a set or cracking. Also, I've read that a longer temper will soften the blade a bit more.
 
The flex in a three point straightening should not cause problems. What you did is what most pros do to take out a warp.

Your procedures sound good. However, I would make a comment about the austenitization temp. 1560°F is a little high. 1500°F is the standard target. Probably no harm done, though.

Finish the blade and test the edge. If it cuts well and the edge isn't chippy or rolls, it is fine.
 
This means your HTed 1080 had a pretty good elastic limit and it will fail by bending before breaking. A room temp piece of D2 would have snapped (experience LOL). All steels flex the same amount the type of steel and the HT will determine where the failure point is and how it will fail. It is safer to do what you did with the blade around 400f. I hate to straighten D2 even at 400.
 
Flex is a factor of geometry. The thinner a blade, the more it will flex. Doesn't matter what the steel is or if it is hardened or not. The difference comes with the elastic limit. That is the point when the flex is beyond the point where the steel can bend further without breaking. This varies with hardness, metal type, and many other HT factors.

To prove that flex is totally geometry related, try bending a short piece of 1095 steel, hardened to about Rc60, in a 360° curve until the ends meet. Impossible....not at all.
Take an old fashioned double edged razor blade and hold it by the ends in your fingertips. Bring the fingers together and the blade will bend in a circle....viola .... 360° flex. ( This demo thanks to Keven Cashen)
 
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