Magnetized Blade/Heat Treat?

redsquid2

redsquid2

Красивы Поросенок
Knifemaker / Craftsman / Service Provider
Joined
Aug 31, 2011
Messages
3,063
So I am drilling holes around a profile. I don't have any other way to cut out the profile, yet. So as I drill my holes, I like to stick a rare earth magnet close to my work, to pick up shavings.

I can't detect any magnetization in my knife blank, but this little magnet of mine does seem to magnetize other things, like drywall screws.

If I magnetize my blade, will that affect the heat treat?
 
No it will not have any effect. Blades have to be heated above non-magnetic to harden them, so any magnetivity will be lost at that time.
 
Thanks guys.
 
Congratulations!!! You just volunteered to do an experiment on this.

I am quite certain that no knifemaker here has ever done this experiment before. Stan and Darrin are right of course, but that is due to the fact that they have spent many years studying metals, heat-treating, etc... But, I don't think that is good enough. I think you should take two blades, magnetize one and then heat-treat them both exactly the same and destructively test both knives and post the results. Obviously, this is very important to you, so let's all learn from your experience.

-M
 
Michael Rader said:
Congratulations!!! You just volunteered to do an experiment on this.

I am quite certain that no knifemaker here has ever done this experiment before. Stan and Darrin are right of course, but that is due to the fact that they have spent many years studying metals, heat-treating, etc... But, I don't think that is good enough. I think you should take two blades, magnetize one and then heat-treat them both exactly the same and destructively test both knives and post the results. Obviously, this is very important to you, so let's all learn from your experience.

-M
Click to expand...

Mr. Rader, that is indeed a brilliant idea for an experiment. Unfortunately, I do not currently have the time or resources to conduct it, since I am developing a revolutionary new device called "the wheel."

-RS2
 
You know what... I'm not sorry. I'm still not trying to cause trouble, but the answer is that no one here has ever done that experiment (I'm quite certain.) So, the challenge stands: give back a little to the other guys here. So many people ask questions here and only a few are generously giving their vast knowledge for free. So give back. Please do this experiment, so that we can know something new. And what if... what if, you do notice a difference? Then we can try to repeat it and, who knows, something new and innovative might actually happen here.

-M
 
Michael Rader said:
You know what... I'm not sorry. I'm still not trying to cause trouble, but the answer is that no one here has ever done that experiment (I'm quite certain.) So, the challenge stands: give back a little to the other guys here. So many people ask questions here and only a few are generously giving their vast knowledge for free. So give back. Please do this experiment, so that we can know something new. And what if... what if, you do notice a difference? Then we can try to repeat it and, who knows, something new and innovative might actually happen here.

-M
Click to expand...

Regarding the idea of "Give back a little.": Nothing has been stolen, nothing needs to be "given back." The two knifemakers who answered my question did so of their own free will, not under duress.

Your proposed experiment would, IMO, be a waste of my time, energy, and materials. In any event, I choose to believe that Darrin and SBuzek are not out to decieve me. I can't imagine why they would be.

I assume the "Question and Answers Forum" exists so that those withmore knowledge can share with those who are less experienced, thereby avoiding the above-mentioned waste, and the frustration that goes along with it.
If my manner of asking questions goes against forum policy, I am sorry for violating forum policy.

If you think forum guidelines need changing, you can talk to the admins.

In the meantime, please desist from jacking my threads. The topic of this thread can be found at top, in my original post. If you want to start a thread about the moral aspects of generosity and "giving back" there is probably a forum around here for that.
 
Last edited:
Getting back on track, I have ground many parts and some knives on surface grinders and blanchard grinders with magnetic chucks, which will magnetize the parts. For the reasons Mr. Sanders stated, it will not effect heat treat. However if you grind with a magnet post heat treat, then they will need to be demagnetized. Especialy if you work in a shop enviroment around steel particles, they will collect on your blade, get in a sheath cause problems etc.
 
JBS TOOLMAKER said:
Getting back on track, I have ground many parts and some knives on surface grinders and blanchard grinders with magnetic chucks, which will magnetize the parts. For the reasons Mr. Sanders stated, it will not effect heat treat. However if you grind with a magnet post heat treat, then they will need to be demagnetized. Especialy if you work in a shop enviroment around steel particles, they will collect on your blade, get in a sheath cause problems etc.
Click to expand...

That is why I also have a demagnitizer in my shop.
Stan
 
Mr. Squid, I think you're taking Mr. Rader too seriously. I'm pretty sure he was just teasing a little, relax man! :D It wouldn't hurt anything and wouldn't cost you any extra time or money to leave one blade slightly magnetic and see what happens during HT. (nothing weird will "happen", but the next guy who asks will then have some proof. Some of us around here are kind of picky about seeing things proven, it doesn't mean we're busting anyone's chops.)

I do believe Messer's JBS and Burek are correct about having a demgnetizer in the shop. (I don't have one but I should) Finished blades hanging around my shop that have a slight magnetism tend to collect fine grinding dust that rusts very easily, and that can have a bad effect on even high-alloy blades. So, let's share tips or links on effective, inexpensive ways to de-magnetize, please? :)
 
Last edited:
Michael Rader said:
You know what... I'm not sorry. I'm still not trying to cause trouble, but the answer is that no one here has ever done that experiment (I'm quite certain.) So, the challenge stands: give back a little to the other guys here. So many people ask questions here and only a few are generously giving their vast knowledge for free. So give back. Please do this experiment, so that we can know something new. And what if... what if, you do notice a difference? Then we can try to repeat it and, who knows, something new and innovative might actually happen here.

-M
Click to expand...

Sample size is too small for anything conclusive. If there was a concern about the end result why not just degauss the blank and proceed with the HT?
 
Relax squid. Michael has a good reputation here and is an incredible bladesmith.(seriously)He really wasn't trying to start trouble. He wasn't sorry for his suggestion is all the way I see it.
No big deal if you don't want to do what he was simply "encouraging" you to do.
As said above. You " demagnetize" the blade automatically at 1414 degrees F.
So it will not affect the blade unless you are finishing the blade to high grits pre heat treat. Then a demagnetizer might help keep inadvertent scratches from the blade.
Happy holidays!
 
I was wondering if one could make a demagnetizer by wrapping an extension cord around a tube so that when electricity is running through the cord (like if some power equipment is plugged into it and running), the alternating current would make flip-flopping magnetic fields strong enough to demagnetize a blade when passed slowly through the tube.??????

- Paul Meske
 
You must log in or register to reply here.
Back
Top