cracked blade?

Will52100

Will52100

Joined
Dec 4, 2001
Messages
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I have never had a 52100 blade crack in the quench befor, this one did it after the 2nd quench. I noticed when I went to heat for the third time a crack right at the ricaso from the tang shoulders.

I triple normalized and anailed the blade, the only thing differnt on this blade is that I used a spring fuller to get the tang shoulders in. Wonder if that's what did it. The blade was finished to 400 grit befor quench, including the tang. The crack kinda folowes the the end of the temper line where I heated the ricaso with the torch.

Any ideas?

Thanks, William
 
2000 Deg.!? Wow, I forg mine at about 15-1600, and since I'm not able to do much reduction I basicly do a finishing heat every heat, takes more time, but I get better performance that way. I've never had one to crack befor though. It's sitting in the freazer right now, and will temper it today, bout time to destroy anouther one anyway.
 
Will,

I like you, forge my blades at 1600 degrees and below. The only time that I have had a blade crack is with a water quench. I normally don't do a water quench but was playing with some information that I had read in a metalurgy book. This blade although I had tempered it back so that it would pass the "brass rod test" still broke on the nintey degree flex. I usually quench in Chevrons' equivelent to Texaco type A oil heated to one hundred and sixtey degrees F. Normally I can flex one of my blades, so quenched to nintey degrees with no signs of stress risers showing in the blade and I have flexed blades one hundred and eighty degrees up to six and a half times and not broken them. What kind of shoulders does your craked blade have and what are you using for oil? Give us a description and we'll try to help.


Bill B.xxxx
 
I'm useing a mixture of vacume pump and atf oil and it is a slow quench. I use it for most carbon steels, with the exception of damascus, that requirs a faster quench.
The shoulders were rounded from the the spring fuller and were cleaned to 400 grit. There were no stress risers that I could see, will know more when I break it. This is the first time I used a spring fuller on 52100 and think maybe the fuller was to cold. Normaly I used the edge of the anvil for the tang, but have found a spring fuller much faster. What gets me is that the crack showed up as I was heating for the third quench, and no, I don't think I got to hot to quike, brought it up nice and slow. It sat in the oil for 24 hours and was not over heated or warped. May have gotten a bad batch of steel as I am useing old ball bearings. One of these days I'm going to switch to round bar.

Thanks,

William
 
I don't think it is your spring fuller that caused the problem, I use a guillotine type fuller made from leaf spring for drawing out all my tangs and never had a crack yet (knock on wood), sounds like you might have hit it one time when it was a touch cold, I to try to forge on the low heat end, and working with a hand hammer it can get in the no hit temp pretty quick when fullering, I'm not saying you did, I'm just suggesting this might be a possibility.The crack was probably there before the quench cycles started, and the expansion and contraction from the cycles just made it expose itself. Just a throught.

Bill ????
 
I think you are right, I destroyed it today, it cut well and was tough, the break in the tang looked clean. I think I took too long to get the tang fullered down and probly should have warmed the fuller. Also posible the oil might have been a little on the cool side.

Would have made a great knife, it cut through nails and mild steel with no damage to the thin cutting edge and sharpened up easily. I have anouther blade from the same bearing race that I'm in the process of heatreating now, will test and destroy it also, don't feel like I have been doing enough of that latly.
 
Cool oil cools slower than hot oil due to the viscosity. The problem could have been from the oil, or a sharp edge right at the ricasso, always keep everything smooth. In order to push steel to the limit, you must have a quench oil that is standard, the same all the time, always. That is why I buy oil with the ANSI specs on them. Otherwise you are introducing variables you cannot define. The low temp forging is the way to push the steel to high performance ranges. Old ball bearings are also introducing variables you can't control, they provide a lot of challenges but be aware that all ball bearings are not the same. They have been made since before 1900 and a lot has changed in that time. The new stuff is awsome. Keep the experimenting up and you will be rewarded. Chasing unknown variables set my progress back, but taught me a lot in the process.
I would strongly sugges you listen to father Burke and try using oil with a known heritage, you won't be sorry.
 
Thanks Ed, I love 52100 as a blade steel, I havent found anything that compares to it. Just have never had one crack on me. Kinda iritating, espaily as it was a custom order.
I holhartedly agree with you on eleminating as many variables as posible, but at this early date, with a three month lay-off, I'm not able to push as far or as hard as I'd like. Not to mention that I am a rank beginner :)

BTW, Ed, I love your book, it was one of the reasons I got into knife making.

Thanks every body,

William
 
Ed,
If I'm father Burke then that makes you GRANDFATHER Fowler.

Will,

I have to agree with Bill ????. I to beleive that you probably hit the fuller when the tang was to cold. I caused some severe cracks in a blade when I was playing with just how cold is too cold to forge 52100. In dim light as the steel strts into the dark red after the phase change it is time to reheat. If your fuller was cold the steel touching it could pass through this temp while the center of the tang still looked hot enough to forge.
Rex Walter sells virgin 52100 at a very reasonable price. His ph. # is 724-752-0742. The first quenching oil that I bought cost around $35.00 for a five gallon bucket and that included shipping. That was three years ago and I still haven't used all of it. I would advise that when you get back to workyou purchase some of each. You could also take some of the proceeds of your next knife sale and do like wise.


Bill B????
 
Thanks,
Burk, I am planning own purchasing some virgin steel, good quaility ballbearings are hard to come by down here, most are now imports, and am tired of 'hopeing' that what I got is 52100 and not case hardened or some other steel, like a larg hunter I that I forged from case hardened steel. The steel I am useing now is a bunch of 20+ year old, unused, new ballbearings that I got at a flea market, but those are fast running out.
The quench oil, still don't quite belevie it's nesasary, but then I couldn't beleive the 24 hour seperation, or the triple quench for that matter, till I tried it! As soon as I can, I am going to get a gallon of Texico Type A and compare a blade of it to a blade of my old quench oil for a comparision. Not that I'm douting anyones work or experiments, I just have to find out for myself, often the hard way.:rolleyes:
As for a blade cracking, I have never had one to crack while hammering on it, all the way to a black heat once. But I was never doing as much moving as I was with that fuller. Also now that I think of it, I had just come from a couple of days welding and drawing out damascus, so I might have been pounding a little to hard. Guess it just bugged me a little.

Bruce, ever since you helped me with damascus, I won't have no wasted blades ever again! They'll make a blade one way or the other, wheather they like it or not!;)
 
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