Why does 1095 need a 10 min soak time, also...

Stacy E. Apelt - Bladesmith said:
Check steel suppliers for 26C3. It is between Hitachi White and Hitachi Blue. Some like to call it "Spicy White". It is very low price. Many of the USA knife and steel suppliers will ship it to the UK.
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Oh nice, thanks, i've never even heard of that steel before, let me go and read up on it and check for suppliers, thank you good sir.
 
Londinium Armoury said:
each ping costing 50 no thanks haha.
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Another way to look at it could be that this will be extra incentive to make sure you pay attention and have everything spot-on each at each step to avoid mishaps as best you can.
Using myself as an example, I got into knife making because of a fascination with damascus and pattern manipulation and have yet to make a mono-steel knife. Putting 3-4 days into making the bar before even starting on forging the blade (only arm and hammer power back then) gave me extra incentive to take as much time as needed to try to make sure each knife was good enough sell. I should mention that I did come from a blacksmithing background, so already knew how to move the metal.
 
weo said:
Another way to look at it could be that this will be extra incentive to make sure you pay attention and have everything spot-on each at each step to avoid mishaps as best you can.
Using myself as an example, I got into knife making because of a fascination with damascus and pattern manipulation and have yet to make a mono-steel knife. Putting 3-4 days into making the bar before even starting on forging the blade (only arm and hammer power back then) gave me extra incentive to take as much time as needed to try to make sure each knife was good enough sell. I should mention that I did come from a blacksmithing background, so already knew how to move the metal.
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Good point, I'm pretty confident I can keep making knives that will turn out good, but I'm not very experienced with clay quenching yet, I've done it a few times messing around with different mixtures of clay, stone and charcoal, added some red iron oxide as well a couple of times which seemed to help, I have used fire cement mortar as well which was okay.
I just find the water quench can be a bit unpredictable. I haven't quite worked out an exact foolproof routine and method yet, I'm not even sure one exists to even aim for. I seem to be doing everything up to standards, getting the water temp just right (hot tot he touch) getting the clay thickness just the right consistency and thickness (not too thick of a layer, a few mm) Making sure I don't clay the upper portion of the spine, putting a thin layer of clay and charcoal along the edge of the blade. Making sure I don't overheat the steel and keep it at a nice dull/cherry red, not going into bright orange etc. It all seems okay theory wise.
I haven't really had many blades crack on me in practice. But when it happens I don't know what causes it or how to correct it in future, it seems to just be random destiny, some blades just weren't meant to be born. Japanese superstition is my best scientific answer. I leave the edges 1-1.5 mm thick so everything seems like I'm doing it right. I just don't like the idea of expensive steel randomly cracking but I will try some white # 1 and white #2 at some point, along with W2 I can get the W2 cheaper than the 1095 for some reason. Not sure why.
 
If you're gonna quench in water, your are gonna have breaks. There's really no way around it.

That's why so many people use a fast oil, like parks 50. It's nearly as far as oil, but not as violent.
 
I have no experience with it, but some people do an interrupted quench, where you would go for 1-3 second in water and finish of in oil. This can apparently help to some degree with cracks caused by water quenching.
Another thing is that you should go to temper immediately after quench, as the differently HT steel will need the stress relieve ASAP.
 
I will explain a bit about what causes the cracks in quenching fast hardening steels like W2, 1095, and other high carbon steels.

Most blade steel is not made to water quench. It has a fair amount on manganese - .over .35% - which increases hardenability. This quenches quite well in oil.
The Hitachi steels and others made to water quench have less than .3% manganese, and the very best, like tamahagane, has almost none. Low alloy content is very important in attaining n active hamon and avoiding cracks in a water/brine quench.

When the steel is heated above the A-1 point it becomes austenite ... which is very soft and rubbery. Upon the quench, if it passes the pearlite nose it stays austenite. The low alloy high carbon steels have to drop from austenitization to below 1000°F in less than .5 seconds. That takes the fastest of quenchants --- water/brine. The fastest oils will work, but don't create sori and the activity in a hamon of yaki-ire.

OK, the steel got past the pearlite nose in a water quench. So far, no problem.
When it reaches the martensitic start point (Ms), around 400°F, it converts to martensite rapidly. The conversion continues until the martensite finish point (Mf) ... usually around 200°F. Because the water quench does that in such a short time this creates extreme stress between hardened and unhardened areas and the blade can literally tear itself apart at it reaches the Mf.

By quenching in water to rapidly drop the temperature below the pearlite nose, and then quickly switching to oil you slow the cooling rate and the stress of the conversion. This is the purpose of a water-oil quench.
 
HSC /// said:
Of course laminated steel solves the cracking problem.
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I've never worked with laminated steel, it scares me, but I've just hooked up a pretty precise filing jig, so I can control the exact degrees of each bevel, so maybe I will give laminated Hitachi steels a go now. Before I was worried because the core is only 1mm thick and I was afraid to grind too much away on one side and rip right through too much of the core.
 
FredyCro said:
I have no experience with it, but some people do an interrupted quench, where you would go for 1-3 second in water and finish of in oil. This can apparently help to some degree with cracks caused by water quenching.
Another thing is that you should go to temper immediately after quench, as the differently HT steel will need the stress relieve ASAP.
Click to expand...
I've never done an interupted water/oil quench before, I have done interupted pure water quenches though and dabbled in them on scrap off cuts of high carbon. I don't know if this has another fancy term or word for it, but it's pretty much the same process, dunk for 2 seconds then take out for a second then back in. I doubt it has the same benefits as water/oil though, because the cooling rate would not be different in each bath. But I think it might help with stress and vapour jacket violence etc.
 
A.McPherson said:
If you're gonna quench in water, your are gonna have breaks. There's really no way around it.

That's why so many people use a fast oil, like parks 50. It's nearly as far as oil, but not as violent.
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This is what I figured to be the case, I kind of knew it was to be expected, all though there are things you can do to reduce the risk, it's always going to be part of water quenching. I have been brushing up on my Japanese curse words though, so i'm ready to rumble.
 
Stacy E. Apelt - Bladesmith said:
I will explain a bit about what causes the cracks in quenching fast hardening steels like W2, 1095, and other high carbon steels.

Most blade steel is not made to water quench. It has a fair amount on manganese - .over .35% - which increases hardenability. This quenches quite well in oil.
The Hitachi steels and others made to water quench have less than .3% manganese, and the very best, like tamahagane, has almost none. Low alloy content is very important in attaining n active hamon and avoiding cracks in a water/brine quench.

When the steel is heated above the A-1 point it becomes austenite ... which is very soft and rubbery. Upon the quench, if it passes the pearlite nose it stays austenite. The low alloy high carbon steels have to drop from austenitization to below 1000°F in less than .5 seconds. That takes the fastest of quenchants --- water/brine. The fastest oils will work, but don't create sori and the activity in a hamon of yaki-ire.

OK, the steel got past the pearlite nose in a water quench. So far, no problem.
When it reaches the martensitic start point (Ms), around 400°F, it converts to martensite rapidly. The conversion continues until the martensite finish point (Mf) ... usually around 200°F. Because the water quench does that in such a short time this creates extreme stress between hardened and unhardened areas and the blade can literally tear itself apart at it reaches the Mf.

By quenching in water to rapidly drop the temperature below the pearlite nose, and then quickly switching to oil you slow the cooling rate and the stress of the conversion. This is the purpose of a water-oil quench.
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Thanks for the detailed response, I will use this as a reference guide, I just finished putting the primary bevels on the first 1095 knife, I made it as thick as a standard tanto (it's laughably thick for a 5 inch blade) it will be getting clayed up in 1 hour when the sun comes up, it's around 6am now.
Then I will be draw filing and sanding the bevels and shinogi to 120 grit, and this evening I will be attempting the yaki ire and yaki modoshi. I will be recording the process, hopefully it all goes well.
Thanks a bunch for your help, it's much appreciated.
 
Londinium Armoury said:
I've never worked with laminated steel, it scares me, but I've just hooked up a pretty precise filing jig, so I can control the exact degrees of each bevel, so maybe I will give laminated Hitachi steels a go now. Before I was worried because the core is only 1mm thick and I was afraid to grind too much away on one side and rip right through too much of the core.
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What part of London are you in?
I’ll be in osterley mid December
 
If anybody is interested in my process with hamon water quench blades and how I make them, I will start a new thread so other people can learn, and more experienced people can give tips and advice. I've just finished claying the blade it is drying now. The process is being recorded, I will post videos in the thread.
 
Barmond steel uk have euro w2 in different sizes.i say euro w2 because it has more chromium than the U.S. version
Gfs knife supplies uk has 26cr3 and other good stuff
 
HSC /// said:
Of course laminated steel solves the cracking problem.
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Oh yeah, that and doing a proper anneal, having a proper clay slurry on the blade before austenitizing, using a slightly lower aus temp and warming up water. And also tempering ASAP. Never had a failure water-quenching this way, even with steels not advised for a water quench (I just warm up the water a good bit more beforehand for these). I must acknowledge your post about yout hitachi steels heat treat did help me an awful lot, thanks for that Harbeer. One thing that is absolutely vital in the process I think is the clay slurry. It does make water quenching a good bit more stable as the vapor barrier is mitigated by the clay. Never tried a brine quench but I guess it might act similar.
 
John mc c said:
Barmond steel uk have euro w2 in different sizes.i say euro w2 because it has more chromium than the U.S. version
Gfs knife supplies uk has 26cr3 and other good stuff
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Both are stunning steels when treated properly, very little difference between both. I mainly use 135cr3 (euro W2) as I get better prices for it than 26c3 in thick stock for forging, otherwise I'd use the 3mm thick 26c3 from GFS in the UK as it is dirt cheap. Aks has it thicker but a bit pricier.
 
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