Straightening high speed steels.

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Feb 19, 2019
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Willie71 Willie71 just heat treated some M2 and M4 for me. I can't wait to put one together and put it to use in my kitchen.

The Zapp M4 came out great but the M2( I don't know the maker) warped. Its at 66Rc so I'm nervous about flexing these at that hardness. I don't know if the high red hardness will affect how well heating it to 400 to straighten it will be successful. Has anyone else dealt with this? Also has anyone else had problems with M2 warping?
 
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Jun 15, 2012
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Just built this straightening hammer from a carbide drill bit and cheapo hammer. 20-30 USD. Frees one hand, compared to the chisel. Works great.
3hZduWO.jpg
 

Matt Rochester

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What’s the thickness? I’ve use a bead blaster to straighten cpm154 and AEBL with slight bows. I’ve only used it with .100” or less stock. Worth a try if you have access to one. I do it after I’ve rough ground the blade right before hand sanding.
 
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I once heard that straightening a knife this way will have only temporary effect and after a few weeks it will curve again. What do you think about that , can it be true or it's bs.
 
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Well it didn't work so now you know. How deep do the divots go and how many is normal.
??? What didn’t work and what did you do exactly?

how many is a function of how bad the bend is. Sometimes you might need to hit it 10 or 30 times or more

How thick is your material?

The divots are probably a few thousand deep and need to be ground out
 

Matt Rochester

Gold Member
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Nov 28, 2014
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I once heard that straightening a knife this way will have only temporary effect and after a few weeks it will curve again. What do you think about that , can it be true or it's bs.
I’ve not had any warps return while in my possession or had any returned. I do have a thin kitchen knife at home that has a warp I can test this theory on. However, since it’s essentially the same thing as peening then I don’t think it will return unless you Grind off the surface area that was peened. I understand that actually peening is much deeper than a bead blaster. This is all assuming you were talking to me!
 
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??? What didn’t work and what did you do exactly?

how many is a function of how bad the bend is. Sometimes you might need to hit it 10 or 30 times or more

How thick is your material?

The divots are probably a few thousand deep and need to be ground out
I ground some masonry bits and used them to make some divots. The divots i made didn't do anything and the bits shattered after a few hits. Looks like I need to get the right tool for the job.
 
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I ground some masonry bits and used them to make some divots. The divots i made didn't do anything and the bits shattered after a few hits. Looks like I need to get the right tool for the job.
The carver carbide tool I mentioned above hasn’t failed me. Previously I tried a carbide drill and it worked but eventually shattered...
 

FredyCro

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Jan 11, 2019
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Has anybody tried using one of these? I accidently stumbled on this in local classifieds, in German its called hartmetall hammer. To my understanding it should be either a hammer with a carbide tip or a softer alloy of carbide. They can be bought cheaply (ca 10 Euro) and are used for masonry work like breaking tiles.

mNwZK0v.jpg
 
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I need to get one of those.

Storm’s M2 was the worst warping steel I have ever worked with. I got things as close as I could, even re-heat treating a few pieces. AEB-l was super easy in comparison.
I was looking at the pieces and it looks like it warped in areas I ground. I wonder if using a dull belt was enough to put stress into it.

I heated it up and used a 3 pin setup and it got some of it but I don't have a good vise.
 

Willie71

Warren J. Krywko. Part Time Knifemaker
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Feb 23, 2013
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I was looking at the pieces and it looks like it warped in areas I ground. I wonder if using a dull belt was enough to put stress into it.

I heated it up and used a 3 pin setup and it got some of it but I don't have a good vise.

I use a piece of 3” angle iron and overclamp the blade for the whole temper.

The blades warped in the same spot each time. (When I redid them) they came out of the plates straight, and warped in cryo.
 
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Apr 15, 2019
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I have a tungsten bit peening hammer. I have used it a decent amount on warped M2 kitchen knives with great results. I just keeps pounding little divots until blade is straight.
 
Joined
Jun 15, 2012
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Has anybody tried using one of these? I accidently stumbled on this in local classifieds, in German its called hartmetall hammer. To my understanding it should be either a hammer with a carbide tip or a softer alloy of carbide. They can be bought cheaply (ca 10 Euro) and are used for masonry work like breaking tiles.

mNwZK0v.jpg

I was looking at one in the hardware store, but the light wieght put me off a little.
I think a hammer is more practical than a chisel though. I have both, but the hammer is just easier and faster to operate.
 

FredyCro

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Jan 11, 2019
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I was looking at one in the hardware store, but the light wieght put me off a little.
I think a hammer is more practical than a chisel though. I have both, but the hammer is just easier and faster to operate.

I guess I will just have to try it at that price point. I thougth it's more about making small indents then putting a lot of power behind them.
 
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