Damaged knife blank. Can it be saved?

ron_m80

ron_m80

Tempered Member
Joined
Mar 1, 2009
Messages
8,155
I am going to try asking this without a supporting picture, and hope that it will suffice. If not I will have to post pictures tomorrow.

I have damaged a nice bowie blank I have been working on. I placed the blank in my vice, and didn't take care to keep the edge from being damaged. Something in the vice, nearly sheared a chunk out of the blade. The damage is obvious, but not complete. If I heat the metal up, will it become homogenous again? Is there something Peters can do with it, if I ask them for an extra service?

Thank you for your time.
 
Without a picture, my best guess would be to grind the damage out and reprofile the edge. Or buy a new blank? No heating repair would work..
 
Much info (beyond a photo) is missing.
What kind of steel?
Is it already hardened?
How big is the "chunk" that is missing?
Is the blade bent?
 
bladsmth said:
Much info (beyond a photo) is missing.
What kind of steel?
Is it already hardened?
How big is the "chunk" that is missing?
Is the blade bent?
Click to expand...

Thank you,

O-1
No missing piece yet, it is just stressed (dented, distorted)
It was annealed when I received it.
The blade is not bent, but that spot was moved out of place.

All in all, its a pretty minor dent, but the metal was moved out of place by shear force while cold and annealed.
 
ron_m80 said:
I did that. I am worried about stress fractures being an issue post HT.
Click to expand...

I'm just thinking out loud here, so take all this with a grain of salt...

I presume you don't have the gear to do a full anneal, forge it straight and normalize/anneal before progressing. But I doubt that's even necessary. Could you do a high temper, say 400F in your kitchen oven, and straighten it while still warm? Take a look at threads by Rick Marchand and others who do their own HT, about how they deal with warpage after quench and/or tempering.

Afterwards, take care to grind the bevels as straight and evenly as possible... both in terms of geometry, and grinding one side a couple passes, then the other to keep heat even, and leave the edge a little thicker than you normally would.

It sounds counterintuitive, but O1 is the only steel I've ever had warpage issues with, and that's the advice Brad gave me.

Once you're ready for HT, it surely wouldn't hurt to inform the crew at Peters' of your concerns. But based on what you've told us so far, I wouldn't be terribly worried.
 
Alright. I will take that information and work with it. The blade is just about ready for HT, so it bothered me that I would damage it this far along. Those darn lessons, :D!
 
Naturally, this stuff only occurs when the blade's almost done. If it happened while it was still a flat bar, that would be no fun at all :D
 
If you want to be on the safe side, have them do a normalization prior to heat treat.
 
Set the blade on something flat and hard...a bar of steel will be fine. Tap the area gently with a hammer, from both sides, to smooth out any irregularities, then file the edge back a tad and finish sanding the bevels. What happened to you happens to everyone at some time or other. It is very unlikely there is any problem with the steel. A photo will be really useful, though.
 
Sometimes I have issues with a file slipping and damaging the edge - which I can usually just reprofile to take care of. If the entire blank is bent along the wrong axis, then I would go with the suggestions of gently hammering or temper at 400+ degrees for a while, and be sure to slide something like a coin under the ends of the blank. That will lessen the chances of having to put it through a second cycle.
 
You must log in or register to reply here.
Back
Top