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The Newbies Arena Are you new to knife making? Here is all the help you will need. |
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#1
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1095 cracking?
Gentlemen,
I just ordered 40' of 1095 and noticed it is said to be not easy for beginners. Cracking was mentioned and I remembered some of my early efforts with 1095 cracked. I think it is too late to change the order but was thinking that the last order of 1095 was 1/16" thick. A friend Master blade smith 'Dan' said 1/16" cools too fast and if I use it remember it must be quenched in under a second! Dan recommended 1/8". But then he makes swords and I make surgical skinners. The new order for 1095 is for 3/32", a perfect blade thickness on paper... a little thicker than the 1/16" but thinner than 1/8". Actually I had never even heard of 3/32" before but have high hopes for this order of steel I can make 60 knives out of. The 1/16" was kinda worrisome to harden as I never know if the ones I made will ever crack after being sold to a customer. I feel better about the 3/32" but am now worried about the 1095. I am not a beginner and have hardened lots of steel before. If they crack they crack. But I was wondering if they do crack, will it happen during hardening or can they crack after being sold to a customer? I cracked several 5 years ago when I was making the 1/16" 1095 blades and kept them all and none have cracked since. The cracks happened while hardening the steel or a day or two after. Am I right that if the blade doesn't crack soon after being hardened it is alright? Should I try and break a few to see how good a job I really did? Why do beginners have lots of trouble with 1095 cracking? I have a propane forge with two big magnets right there and quench in used motor oil with 20% transmission fluid mix in it. I ain't no beginner well... maybe I am... What do y'all think? Thank you... Jack the Knife Sandymay and Dukedog |
#2
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A blade could crack at any time but it is much more likely to crack either during the quench or between the quench and the temper. Since you are using oil a crack during quench is less likely. If you can get your hands on some pro quenching oil it will be even less likely. The most important thing for you will be to get the blades into the tempering oven ASAP after quenching - let the blades cool to under 150 while sitting in the oil, dry them off, and into the tempering oven right away.
And Jack, if that means you have to make less than 2000 blades in a batch then so be it..... |
#3
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Howdy Ray,
Thanks, Shouldn't I hold the blade in the tongs and... {I don't know when the blade is 150 degrees}... as soon as the smoke from quenching abates and the blade can be handled, wipe the blade and set it in the tempering oven at 400 degrees for an hour? {rather than lay it down in the quenching oil?} I could temper it faster that way. Are you still married to the Chinese chick? Jack the Knife |
#4
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Ray,
I contacted Admiral Steel and they haven't received my check yet. It is not too late to change my order from 'cold rolled annealed 1095' to 'cold rolled annealed 1074-5' Is 1074-5 hard enough for a small skinner? If so I have time to change the order and avoid the cracking issue. Help! JacktheKnife |
#5
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With your setup you are more likely to get 1075 hard without worring about cracking than 1095. I like to soak 1095 at temp for about 10 minutes before quenching. That would be very hard to do in a forge.
__________________ Barry Clodfelter Proud member of PETA....People Eating Tasty Animals There is a place for all of God's creatures...right next to the mashed potatoes and gravy! |
#6
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I'm not certain what your friend Dan means that the 1/8" 1095 cools too fast. I does have less mass to cool, if the other dimensions are the same, but there is little difference in the rate of cooling between the outside and the core of a blade at that thickness. What you have to worry about is the thinner parts cooling at a different rate than the thicker parts.
What you could try is marquenching. Heat the oil to about 425-450 degrees, for the 1095, and quench it long enough for all parts of the blade to come down that range and then pull it out and let it air cool. Bringing the temperature of the steel down to just above the Ms point will give about 2 minutes or so to cool to under the Mf point, a matter of about 200 degrees. I actually hold the blade in the quenchant until the color disappears from tang to avoid quenching it. That way the thin and thick parts of the blade undergo conversion to martensite at close to the same time, reducing the stress on the blades. Admiral's 1074/75 should be fine for making skinners. It shouldn't form proeutectic cementite, that is cementitie, that is not part of the pearlite structure, but it should still have good wear resistance properly hardened and tempered. It is still a shallow hardening steel that doesn't give you much time to avoid the nose of the cooling curve so you will still need a more agressive quenchant. A vegetable oil may well do. You will just have to try it out. However you go, do what Ray said and don't hold your blades aside as you quench and put them into the tempering oven in a batch. Put them in as you quench them to reduce the stress as quickly as possible. Personally, I don't see why a blade that has been properly tempered should crack under normal use after being delivered to the buyer. Doug __________________ If you're not making mistakes then you're not trying hard enough |
#7
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When I said 150 degrees that's just the point at which most people can more or less comfortably handle a chunk of hot steel. So, hold it with tongs if you need to but keep it in the oil until you can hold it in your hand, then temper.....
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#8
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Ray,
I stayed with the 1095 and understand that as soon as I can handle it wipe the blade and put it in my little pre-warmed, electric tempering oven at 400 degrees. It's good to be back in the knife business Thanks... Jack the Knife |
#9
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Oh and don't forget to hold your tongue right that might help alot too sorry I'm going to find out how good or bad 1095 is very soon, I have 2 blades made from it that I am going to tackle the HT myself and trust me my tongue will be held right haha
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#10
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Done properly the 3/32" 1095 will work fine, I do quite a few blades out of it myself.
The 2 main culprits with cracking are cooling it too fast (usually using water instead of oil) and getting it too hot prior to quenching. Once you get the process figured out you should crack very few blades. And as others said, the cracking is most likely to occur during and right after the quench. Just get it into an oven asap. One thing I *highly* recommend is doing a few normalization cycles before heat treating. The cold rolled Admiral steel has a lot of stress in it from being rolled out. Normalizing will relieve the stress and really cut down on blade warpage during heat treat. I do my normalizing before grinding the blade because sometimes they will even warp when grinding. |
#11
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All said and done, what it comes down to is that 1095 can be heat treated. It's just easier with some melts than others. Even though there are makers who quench in water and brine without a lot of problems with cracking, it makes no sense, at least not to me, to invite trouble if you don't need to. Go to the faster quenchants only if slower ones won't do the job. Also, watch the stress risers. Maybe grind out to at least 220 grit and eliminate sharp inside corners from your work.
Doug __________________ If you're not making mistakes then you're not trying hard enough |
#12
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Is there a way to tell if steel was cold or hot rolled?
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#13
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Metal99,
The steel I ordered was 'cold rolled'. I don't really know what cold vs hot rolled means but the steel that is coming is said to be cold rolled. I finally figured out PayPal and Admiral has been paid. I should have some steel in 10 days at the most. JacktheKnife and Dukedog... Sandymay disappeared a week ago. She is almost 12 and has lived here with me for 7 1/2 years. I have wore blisters on my heels looking all over the woods for her. There are signs with $100. reward up and it is past hunting and trapping season. She wasn't stolen, shot or trapped, She was in great health and besides sleeping most of the time {like me} the best hunt we ever had was the last two coon this year, just a few months ago. I was going out again today {Sunday} to walk the woods looking for her but now I am looking for her body. No Hogs around here now, Coyotes don't kill big hounds either. Maybe someone will call and say they have her. Here's a story about what I hope, wasn't our last hunt. http://www.coondawgs.com/forum/viewt...?f=27&t=148347 |
#14
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Cold rolled has a slick shiny finish and hot rolled has a thin blackish scale on it....
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#15
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Jacktheknife, Sorry to hear about that man. I hope you find her.
Ray, I have cold rolled 1095 there was no scale on it just a semi smooth glossy grey finish. Thats good to know thanks Ray. I will be sure to anneal it before heat treat. |
Tags |
1095, blade, cold, forge, forging, grinding, hammer, handle, heat treat, hunting, iron, knife, knives, steel, tang |
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