Thanks Pete yes a lot of work goes into them for sure:)

Hi Jason, I'm OK thanks, just getting a bit older:). Shushhhh. Don't give the one legged stance secret away or we will all be done for:))

@@Jackloreknives I know what you mean about getting older,I had my 48th birthday last Thursday then did my back in on Friday lifting a bag of hay (it was a ton bag of hay,Ha)

@@Jackloreknives he didn't say which leg though! 🤔

The bear fighting knife would have probably been better off with a differential temper, an extra springy spine with a hard edge is pretty much ideal for knives that are meant to take extreme levels of abuse but are still needed to actually cut things.

Honestly you'd have been better off with a harder tempered 5160. Depending how hot you tempered you may have run into the tempered martensite enbrittlement range of 450-650f where it's both softer AND more brittle than before that point. A tougher steel made hard is tougher than a hard steel made soft, unless you get into marteming and austempering shenanigans.

@@mikafoxx2717 I used an oven and did a single cycle to spheroidize the steel as I double checked and it didn't come that way, it was hot roll 1082 nominal and came inconsistent. I got it from the Blacksmithing Shop at Mayfield Community College. I contemplated making it out of 1080 with a 15N20 core, but had never forged a double edge before. I heated it to 1470 for 12 minutes and quenched in brine at 120 degrees. Then after a quick wipe immediately placed between 2 blocks of dry ice overnight then tempered it at 700 degrees for 2x 2 hours. I used the same formula I did with machine parts, but used a -40 freezer as using dry ice mixed with alcohol only gets down to around -75-85 and wastes a bunch of dry ice. Placing the blade between the blocks gets it down to at least -105.

These days I just preheat the kiln to hardening temp. Put the knives in and time your soak time from when the kiln returns to hardening temperature. The only pre heat treatment cycle I run is a strain relieving cycle

How the hell did you know that? This knowledge is not supposed to be shared publicly:)

@@Jackloreknives the 'EDC' folding knife collecting community in the U.S. seems to be having a flap right now over Rockwell hardness of M390. Independent tests seem to show Italian factories especially (e.g. Lionsteel) as producing not up to many's expectations of what M390 and these super steels are capable of. Edge retention is an easy test for youtubers to carry out so it seems to be the thing they care about. They're not amused when a chinese D2 knife is harder than a Western $500 'super steel' folder. Anyway, I'm not sure what to make of it all but sub 59 does seem a bit low for these steels in this market.

Make sure your quench tank is sufficiently large enough for the amount of blades your going to harden.

Much darker. It all depends on where your as quenched hardness is and also if you have any contaminents on the blade or in the oven. All this will effect temper colours, you can't absolutely trust colour so you will need an accurate thermo couple. Sandy

With 01 it doesn't appear to make any difference. I would not advocate leaving them in there for excessive amounts of time but I have left test samples soaking for an hour without any detrimental effects. Ofcourse you have to protect from decarburisation and ensure you have an accurate kiln so as not to overheat the blades. So long as you keep the blades in the lower part of critical range(780 to 800 centigrade) you will not get grain growth. I am not a metallurgist but understand that the addition of Chromium in the steel will keep the size of the grains small (called pinning the grain boundaries) unless you go above the critical range. Overheating 01 will cause grain growth However other steels will not behave in the same way. 1095 would grow grain if left for prolonged periods so I understand.

@@Jackloreknives thank you for details. I have't used O1 , I'm from Europe and is not so easy to get it here. Keep up the great work and awesome videos.

@@IonutJaR There are many very close equivalent steels to AISI 01 available in Europe.

Yes ofcourse it will. Just make sure you don't test right next to another indentation

Hi Jim, Good question, here's the answer I have a quite large quench tank and even after the last blade has been quenched the oil really hasn't heated up much to make any difference. With 01 you have around 8 seconds to drop the temperature from the Austenitizing temp to around 600C which is where the pearlite knee starts. You'll drop that temp fast enough even in hot oil but having now quenched a couple of thousand knives I like my quench bath oil temp to be around 40C when I start and it'll be around 55 to 60 C when the last blade is quenched. I check each and every blade for full as quenched hardness and expect 65 to 66 HRc with every blade. There is no difference in hardness values from the first to the last blade. I also aim for a final as tempered Rc value of around 59 and to achieve this I'll be tempering above 250C .If your not able to soak your blades you may find your as quenched hardness values may be lower and therefore a subsequent lower tempering temperature will necessary to facilitate your required RC values. You don't want your 01 knives too hot, the lower end of the austenitizing range is what your after, and a good long soak at that temperature to ensure all the carbides melt is needed to get the best from this steel. Sandy

@@Jackloreknives Thanks Sandy, that makes perfect sense and I didn't even think about the size of the quench tank. I have 2 different tanks I use. 1 large and 1 smaller. I use the smaller one when doing smaller knives which I do a lot of. I may need to rethink that because using my large one would then allow me to do one right after the other with having to let the oil cool. My small tank is a 1 gallon paint can and my large one is a 5 gallon ammo container. Thanks for responding that helps me out a lot. Cheers!