What do you think about this?

[kile]

I just heat treated my first batch of 0-1 blades. I heated them in my bbq, and quenched them in vegetable oil. I did ten blades like this. I have one blade that has been my test blade, becuase it turned out really ugly. Any way here is my story. I tried to heat treat this blade with a torch 3 seperate times, and it didn't ever work right. The first time I tested the blade I tried to pound it through a 16d nail. It just got all deformed. The part of the blade closer to the tip deformed a lot less then the portion of the blade closest to the handle. I tried it in the bbq today, it was red hot, and non magnetic, after I quenched it I tried to pound it through the nail again. This time it would cut about halfway through and then the edge would chip off, I figured this meant I had successfully hardenend it. Then I did the rest of the blades in the same manner. I then put them in my oven and 425 for 1 hour, then let them cool to room temp, then I put them back in at 425 and left them for about 1 1/2 hours, because I fell asleep. I tried to pound the same knife through the nail again. I hit it on the spine very hard with a 23oz framing hammer, and the blade broke in half in almost a straight line from spine to cutting edge. I lost about a 2" portion of the blade, I then took this portion and pounded it in to a peice of wood tip first about 3/4" into the wood, then I smashed the remaining part of the blade peice sideways with a hammer, and it came out sidways exactly the same as it looked when I had pounded it in, then I did it again and i broke off a 1/4" peice of the tip. I then pounded on the spine of the remaining peice and it split the wood like a chisel, and I could not break it anymore. I pounded the chunk back through the nail, but because I had to hold it with my fingers I couldn't take full swings but it did cut into the nail and it didn't chip or deform. The knife was 1/8" stock with a hollow grind made on a 8" wheel. Should the knife have broken apart the way it did, or is there something wrong with my heat treating.
sorry about the long post, sorry it it is hard to follow, I am very tired right now.
thanks for any help
Kyle

 

[exsanguinate]

Try the brass rod test to determine edge hardness. If you want a "tough" knife, edge quench. This will allow for a hard edge and a tough spine. That's what I did with this knife. You can see the temper line.

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Ed Caffrey taught me how to do this.

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The Edge

[This message has been edited by exsanguinate (edited 05-02-2001).]

 

[Bruce Evans]

You probably cracked the blade the first time you tried pounding it through the nail...If you are going to pound on the spine you will definately need to differentialy heat treat your blades,at least just edge quench this way the back edge is soft and will take the abuse of the hammer striking it...You should be able to cut a nail,I have cut open 55 gallon drums with mine before and also beat on them with a 8 pound sledge hammer to cut metal,I wouldn't suggest this severe of a test but I was kind of showing off at the scrap yard and decided to try it and I didn't hurt my knife at all,sometimes I would make the edge skate on the metal when cutting and that was the only time I dulled the knife other wise it would still shave after cutting a barrel open,I have also had it used as a ice pick to defrost a freezer before and that didn't hurt it,My step sister's can opener went out on her and she couldn't find her manual one so she took hers that I made her and would open the cans she needed when cooking dinner,She did this for about 2 weeks and I only had to sharpen the knife once a week for her(her and her husband have a horse ranch and so she uses a knife all the time,she carries hers on her belt 24-7 I have even seen her with the knife on when wearing a dress out in the evening,and she is a little petiete lady that you wouldn't think would carry something like that.)
Sorry I got a little carried away here...
Just keep playing with different combinations on your heat treat and you will find that edge holding that you are looking for...Also a hollow ground blade is awful thin to try something like this with,unless you are leaving the edge a little thicker and then convexing your edge on rather high up the blade.
Bruce

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Bruce Evans Handcrafted Knives
The soul of the Knife begins in the Fire!!!!!
Member of,AKTI#A000223 and The American Bladesmith Society

 

[steve f]

[ Kile, The important part isn't wether the blade bent or broke, its that you have taken the time to experiment and test your methods. If you continue to these things you will end up producing good blades of consistant quality. Keep it up..

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Steve Filicietti
Custom Knives
AUSTRALIA
http://www.unitedbladeworx.com.au

 

[kile]

Hey Bruce,
when I heated the blades, they were only red hot and non magnetic about 3/4 of the way up the blade, the magnet still stuck to the spine, also when i quenched them I stuck the hole blade in the oil, then when it stopped smoking and bubbling I pulled the spine out of the oil so that about 3/4 of the blade was still under the oil. Are you saying that I probably cracked the blade when I was pounding before I tempered it? That would make sense, becuase the crack was right in the middle of the spot where the edge had chipped when I pounded it into the nail before. I wasn't pounding on the same spot as where the blade cracked. Also the knife wasn't sharpened, it was still left with about 1/16" thick metal along the edge. That is why I think I didn't go all the way through the nail, there was no sharp edge.
Kyle