Burnt tip of knife... can it be saved?

[texas gun person]

This is my 3rd knife that I was working on. I know what I did wrong, which was getting it too hot on the belt grinder. It's 1080 that has been heat treated. Anything that can be done?

It was looking so much better than my first two... until this.

 

[timos-]

youll have to grind off the burn part

 

[3fifty7]

Shorten it .25”

 

[Hubert S.]

You should grind that off. If you plan to do more work on the bevels, do that first and regrind the tip later, otherwise you might have to shorten it twice... Maybe use a new grinding belt to finish it, worn belts produce a lot more heat.

 

[texas gun person]

Got it. Thanks, y'all.

You should grind that off. If you plan to do more work on the bevels, do that first and regrind the tip later, otherwise you might have to shorten it twice... Maybe use a new grinding belt to finish it, worn belts produce a lot more heat.

Yeah, I'm just getting started, and I'm pretty sure I'm using belts a lot longer than many on here do. Trying to be frugal about it.


Edit: Huh, I didn't realize I had made an account 11 years ago when I did forgot my password...

 

[argel55]

Use a coarse belt so it will grind fast and take it off as the others said.

 

[Stacy E. Apelt - Bladesmith]

I would finish it as-is and if the tip seems too soft (bends easily) ... then shorten it.

Unless the tip turned red when grinding, just because it turned blue when overheated for a second does not mean it is ruined. The color indicates the temperature rose to around 600°F. That will lower the temper a point or two in the affected area, but not so much as to make the knife unusable. And it will only lower the temper in the area that is blue. The rest of the blade is unaffected. A tip that is a tad lower in hardness is not such a bad thing.

In doing nitre bluing (hot salt blue) you quickly dip the blade in 600°F molten nitrate salts in a low temp salt pot. This short rise in temperature does not penetrate into the steel and affects only the surface.

I just looked at the charts and a 1080 blade at 600°F is Rc57-58. The toughness goes up as the hardness drops ( a good thing), so the tip should be fine if it didn't get much hotter. Even at 700°F it is still Rc52.