steel...... warping while you watch

H

Hmathews

Joined
Feb 22, 2005
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I ground (still can't forge anything because of my wrist, so hold down the comments about that if you would, I'm making them how I can :D) a bowie blade blank out of a piece of straight 1 1/2 x 1/4 inch 1095. The blade is 12 inches long with a tang about 5 inches long. I left it on a table while I fitted a guard to another knife I was working on. When I came back to the blank I had just ground, it had bowed up in the middle more than 3/4 of an inch measured to the bottom of the bow when placed on a flat surface. I thought Charlie was pulling something on me, but he swears he hasn't touched it. I have never seen this happen before and wondered what was going on and what could I expect from this blank if I continue with the knife. Any ideas?
 
Harry - I'd bet there was already the start of a bow in the bar before you ground it, sometimes they seem to become more pronounced after we grind. Did you get the blade really hot when grinding?
 
3/4" warp???

How hot were you letting the blade get while grinding? The only time I ever saw something like that was with a guy who made himself a jig and was grinding the bevels almost to cherry red, one side completely at a time.

Are you 100% sure the 1095 was straight to start with? Almost all my 1095 has a bend to some degree when its hot rolled....but i doubt you'd have missed a 3/4" bend.

Seriously....got a pic? a 3/4" bend is huge.
 
All I did to this piece of steel was cut a 17" piece off of a bar 60" long and profile the blade. The flats have not been ground yet nor has the taper been put in the blade. Most of the metal removed was with a band saw. The blade was held in my hands the whole time and never did it get hot enough that it couldn't be held. It never changed color anywhere. The original blank might have had a little bend in it but not enough that you would be concerned...not more than 1/16 of an inch end to end. Charlie thinks the steel might have been miss marked and is actually 5160 and it's "spirit" wants it to be a truck spring. He gives me a hard time about my carbon steel, forging and all.... I like working the stuff, but also like to know what state of mind the steel is in when I start and this is a little puzzling.
 
Hmathews said:
All I did to this piece of steel was cut a 17" piece off of a bar 60" long and profile the blade. The flats have not been ground yet nor has the taper been put in the blade. Most of the metal removed was with a band saw. The blade was held in my hands the whole time and never did it get hot enough that it couldn't be held. It never changed color anywhere. The original blank might have had a little bend in it but not enough that you would be concerned...not more than 1/16 of an inch end to end. Charlie thinks the steel might have been miss marked and is actually 5160 and it's "spirit" wants it to be a truck spring. He gives me a hard time about my carbon steel, forging and all.... I like working the stuff, but also like to know what state of mind the steel is in when I start and this is a little puzzling.
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Something seems way off, then. My uninformed guess is that you bent it somehow while profiling or bandsawing. I've never seen unheated steel spontaneously warp 3/4" of an inch.
 
I make knives nearly every day. Have since 2002. From steel that varies in thickness from 1/16 to 1/4 inch in thickness, some as narrow as 3/8 inch wide. Haven't bent one yet while grinding or sawing one out. I don't really know what you could do that would cause it to bend later. We noticed that it was bent and laid it back down and came back the next day and it was bent nearly twice as much as it was when we first noticed it. This blank had the most even bend from one end to the other you ever saw. The blade varies in width from 5/8 inch to 1 1/4 inches. If I had bent it, it would have been bent more in the narrow areas than it would have in the wide ones. I straightened it out in a vice and can tell you that it takes some stress to bend 1/4 inch steel that wide. It was not bent when the profiling was completed. It bent later.
 
Hey Harry,

I hate to be the one to bring it up, but....

  • Have you had Charlie take a lie detector test yet?
  • You haven't been hearing any Rod Sterling like theme songs in you shop lately, have you?
  • Do you frequently have stuff come up missing, or get moved, in your shop? If so, you may have an overly mischievous shop gnome(s) messing with you!
  • Do you otherwise have a reputation for hallucinations and persecution complexes?
  • When was the last time you had your shop tested for plumb? Maybe your bar IS flat and everything else is out of square.
  • Have you had yourself tested for telekinetic powers? Perhaps your mind is warped and it is starting to be reflected in your work.
  • Are you sexually healthy with no other signs of impotence or limp bent d_ck phenomena?
  • How many years have you been exposed to the breathing of--carbon steel alloy, grinder, forge, heat treat, quenchant and etchant--dusts, vapors and fumes?
  • When was the last time you took your annual knife maker brainwave analysis clearance exam? And what were the results?
CAUTION: Please don't under take any of the above diagnostic assessments without the care and guidance of a conclave of qualified steel magi!

Oh ya, Are you 100% sure of the steel? Is there any chance it could be something else (like 5160) off a roll?

All the best, Phil
 
Hmathews said:
I make knives nearly every day. Have since 2002. From steel that varies in thickness from 1/16 to 1/4 inch in thickness, some as narrow as 3/8 inch wide. Haven't bent one yet while grinding or sawing one out. I don't really know what you could do that would cause it to bend later. We noticed that it was bent and laid it back down and came back the next day and it was bent nearly twice as much as it was when we first noticed it. This blank had the most even bend from one end to the other you ever saw. The blade varies in width from 5/8 inch to 1 1/4 inches. If I had bent it, it would have been bent more in the narrow areas than it would have in the wide ones. I straightened it out in a vice and can tell you that it takes some stress to bend 1/4 inch steel that wide. It was not bent when the profiling was completed. It bent later.
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Well I guess its a mystery, then! :)
 
:D Now I have to have my keyboard replaced. I just blew Mountain Dew all over the place laughing at that and I do worry about Charlie sometimes. I came back from a family vacation and he had welded my vise shut and a hammer to the back of it. He is just as likely to hand you a hot piece of steel to look at as he is one that is coated with super glue.

If I was working in this shop by my self I would have never mentioned it, but it has got to have a logical explanation. I don't care what EF says the only "Spirit of the Steel" is a name of a knife show.

We learned years ago that you mark every bar of steel with the type in several places. We keep our steel in seperate bins. It is 1095. It would worry me just as much if it were any other steel we use. It has us stumped.
 
It needs a good normalizing. Built up stress in steel can cause warping while grinding.
But that is excessive to say the least.
 
Thanks David, Phil & Don. We had decided to take it through the normalizing process tomorrow just so we would know for sure what we are dealing with. Just haven't seen anything moving around like this before. Of all the steels we have used 1095 seems to come with the most problems. The first 1095 we ordered came with a spring temper.

I'll give this stuff a few rounds of heat tomorrow and see if it has the movement cooked out of it. Hopefully it will end up on the table at the Blade Show looking a lot like a bowie. Thanks again.
 
Harry,

I have had some 1095 that did some similar tricks, however, not quite that much. Normalizing really helps, and straighting with a wooden mallet between heats seemed to do the trick.

I have had lots of problems lately with O-1. It wants to hang a hard right in the quench and I can't figure it out. I've never had problems with O-1 in the past, and this just really agrivates me.

I will, however, have to agree that Charlie bears watching.:D

Robert
 
Charlie suggested that I grind the edge only on one side and that it would likely straighten when I heat treated it. It would be just about worth it to try that to see what would happen.

Rob if someone wanted a knife that would cut around a corner I could help them out.

Aren't you left handed Robert? Try quenching it using your other hand and see if it goes the other way.
 
Hmathews said:
Aren't you left handed Robert? Try quenching it using your other hand and see if it goes the other way.
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Now why didn't I think of that? All I have to do is quench twice. The first quench (left-handed) will warp the knife to the right, then the second quench (right-handed) should bring it back to center.

Its amazing at the information you can get here on the forums.:D

I'll see you and Charlie at Blade.

Robert
 
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