Fehrman 3v compared to Nathan's 3v

jdm61 said:
Devin Thomas said that the LONG cryo precipitates those little carbides that do just what you said with AEB-L, which , of course, does not have the larger primary carbides that other higher alloy steels do. I am as far from being an expert on these things as one can get, but it seems the the Landes/Nate method may reduce the drop in toughness that you see going from 58-60Rc with 3v using the "normal" method. According to Crucibles data, when you do that using the high temper, you apparently end up with a product that is only about 25% tougher than A2 at 60 instead of one that is twice as tough at 58Rc as A2 is at 60Rc. Part of that may be the cryo which we know adds a point or so of hardness on its own to these alloyed steels. Having the steel 2 points higher is obviously going to help significantly with abrasion resistance. The question becomes how much MORE does the low temp/cryo method do? Do we get even more fine edge stability that 3V normally gives us? Herr Doktor Landes says that is appears to have benefit with most higher alloy steels. IIRC, he did his dissertation work using RWL34. The other thing that he suggests is quenching in water when you bring the blade out of the temper oven to avoid some minor embrittlement issues. More toughness to be squeezed out of the steel even in the later phases of HT.
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Dan Keffeler said he don't like high temper because he found the edge too chippy.

Dan probably one of the most experienced maker with 3V since he is the few who make extreme application from 3V... something like large wakizaki with very thin edge and chop ton of tree with it.
 
Nathan the Machinist said:
I think this is very true. The most current metallurgy text I have is Tool Steels, 5th edition, and there is a ton of important information in it that wasn't in the 4th edition. That shows things are still developing even in old well established materials.

I believe there are some quirks with particle steels that has received no discussion anywhere at all.

There are some obvious limits to what any of us here are going to "discover" in the field of metallurgy. But some educated guesses and some blundering around with careful controls and observations really can yield demonstrable results even in cases where there isn't a good theory why some things happen. This is the value of real testing.

I will say this: Crucible doesn't appear to be optimizing their materials HT for cutlery. It may not be important to them, or perhaps they're just ill equipped to make meaningful observations as it applies to knives, but I think their suggestions leave some low hanging fruit.
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Do you guys remember Tom Johanning? He made a knife from Modified A8 and the few people I knew that got one said it was one of the toughest knives they had ever used. I wanted one, but the design did not fit my wants so I never got one. In any case he was using a heat treat with cryo between temper cycles I think. I mention him, because of the type of family of steels it is. Again 8% chrome. Problem is that no one makes two knives with the exact same HT, except one adding cryo to the process and one not.
 
Bump this up from the dead, for possible reviews of nates knives.
 
I have an old custom Fehrman Hood Hunter in 3V which is a fabulous knife. If Nathans is all that and more then it must be a helluva knife.
For anybody interested there is a thread discussing Cliff Stamp's idiosyncratic opnion of 3V in big knives, whcih is an opinion I don't share
 
HJK said:
I have an old custom Fehrman Hood Hunter in 3V which is a fabulous knife. If Nathans is all that and more then it must be a helluva knife.
For anybody interested there is a thread discussing Cliff Stamp's idiosyncratic opnion of 3V in big knives, whcih is an opinion I don't share
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Cliff must have changed his mind because he has a Silverback in 3V made by Dan Keffeler and it seems like he loves it.

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Cliff Stamp has been removed from a number of knife forums .

We KNOW what particles will do because we can see [ dislocations vs particles ] it in video taken at very high magnification !!! No guessing , no feelings !! Small particles and the cohesion associated with them DO strengthen the metal !!
Want the optimum strength ? Do Cryo and make sure you don't destroy the cohesion. Stick with the basics , the same ones as we seein secondary hardening !
 
Im curious as hell, why did he get removed? I love that guy, Ive learned much from him, and admire his knowledge about knife steels. Is it the fact that he doesnt sugar coat stuff? Cause I dont either
 
CaptainPicardX said:
Im curious as hell, why did he get removed? I love that guy, Ive learned much from him, and admire his knowledge about knife steels. Is it the fact that he doesnt sugar coat stuff? Cause I dont either
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It's ancient history
 
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