Search results

"...I have to stick with my principles..." That is but ONE reason we respect you so much, Kevin. About P50... my experience has been very good using it with steels like 52100 (never have used 5160) and even Cru Forge V and 1.2442. I did have one problem just the other day using P50 on a...

Ed, you have vastly more experience making and heat treating knives than I do. I am by no means a metallurgist. I don't have my PhD in heat treating...yet! ha ha I'm always learning, and I want that to come thru when discussing opinions that may differ from others. Yes, trying to be...

"My reason(s) for not recommending soaking (during the hardening process) is because there is a VERY fine line between getting everything into solution, and blowing the grain size way beyond what it should be." My understanding of soak is that it is steel dependent. You wouldn't soak 1095...

Right.....I don't make pry bars, either. I really could care less about how my knives bend or don't bend. I want them to cut, and cut long. However, this concept/question creeps up now and again, and lots of folks simply refuse to accept the fact that HT has nothing to do with flex, that it...

Thank you so much, Kevin. Makes a LOT more sense to me now. That "flex" is different than "bend" is key to understanding this topic.

I am posting a quote from Kevin Cashen made on KnifeNetwork way back in 2011, was hoping Kevin or anyone can help to clarify. I am confused on the whole bending/force/geometry/HT thing. Terminology is extremely important especially in this discussion. I hope I don't bugger things up. "How...

Kev, no one direct answer to this. Assuming that you're asking if you can simply re-harden the steel. Technically, no......you "should" do an anneal prior to re-hardening A2. But....there are testimonies from A2 gurus that have re-hardened A2 without problems. From what I understand, the...

Thanks so much, Kevin! Nice explanation. I've been giving the O1 and O7 fine spheroidized steels a 20 minute soak....hoping that is long enough without being too excessive. If I understand correctly with long soaks, as long as the Tungsten carbides (some O1 has a touch of Vanadium as well)...

Wow. This WHOLE time I've been soaking W2 for 10-15 minutes. This AFTER normalizing 1650F, air cooling only, thermal cycling down as we do, air cooling only. No anneals, all this done after machining. Matrix should then be fine pearlite....and I am soaking that, and I should NOT be soaking...

If you have a port, stick a telescoping magnet in there. As we know the magnet will no longer stick in the 1414-1425F range. That's not 1475, obviously, but close. I've heard table salt melts right at 1475F. Maybe you could sprinkle some on a blade and watch thru the port as it melts? I...

The reason people are oil quenching steels that are traditionally air cooled/plate quenched is that it is said to actual allow for LESS retained austenite, and any unwanted precipitates. In other words....a more complete quench from austenite to martensite. Maybe splitting hairs here, or even...

As far as AEBL goes, which indeed Sandvik copied as their 13c26 steel, the Mf point is around -95F, so dry ice slurry would finish the martensite transformation for that steel. I think many of the higher alloy stainless steels and tool steels have their Mf point around the dry ice slurry temp...

Ha! Ted, believe it or not, last night I was loosing sleep over my comment to you! You corrected me, and rightly so, that you weren't questioning the science...but rather some of the claims being made. How right you are on that, too. Not just cryo treatments! When selling a knife in A2...

Ted, there is nothing subjective about it. Take a steel and like A2 and do the "standard" HT, 1750F 30 minute soak, plate quench, then take a hardness reading. Then, do either a sub zero or a cryo treatment, and take your reading again. You will find, on average, a 2-3 point gain in...

Full on "Cryo" (LN2 -300F) is said to allow for the formation of small "greek letter" (it's all greek to me!) carbides that precipitate upon tempering (if the alloying is there). "Sub Zero" (dry ice -100F) is not cold enough to do this. The main reason to use "sub zero" or "cryo" is for the...

This is an excellent paper on CPM M4 heat treating (Darrin's HT looks like maximizing wear resistance) https://ir.library.oregonstate.edu/xmlui/bitstream/handle/1957/54906/LianSidi2015.pdf?sequence=4

Tthat is a misprint. A2 has around 5% Chromium, but D2 has 12%. Someone just made an error in combining A2 and D2 numbers when making that document. Same with the carbon content. A2 has (usually) 1.05% carbon, while D2 has 1.5%. Looks to me like they just threw in the D2 numbers on the max...

Scott, check out that Mn count on the White 1 equivalent steel. Max of .25% and basically NOTHING else in the steel besides the carbon and a sneeze of silicon. It will indeed require an exceptionally fast quench. Parks 50 oil should handle it (we're talking about 1/8" thick no thicker), but a...

I also aim for balance point to fall right at the handle/blade junction, right at the pinch grip, regardless of kitchen or hunting knife. Thin, light, and balanced.

When I received the P50 it said the same thing.....do not use above 120F. It is best in that room temp range up to around 120F max. Temp in the garage is around 85, I take it out in the sun for an hour to bring it up to 95-97. Probably no difference, really, but I do it anyway. Wire loop...