Dan and Jerry's knives are all about the alignment of the steel's crystals. the carbides and ferrite bands line up to form tight, uniform grain that can achieve a high hardness without becoming brittle or needing a high carbon content. They could have probably used a lot of different steels with the same or similar results. We all know it's largely in the heat treat but i'm also willing to bet there's a cap in the carbon content they wouldn't go past. My guess is .7% but i pulled that right out of thin air, no scientific explanation or reason whatsoever. maybe in the austenite or martensite a higher carbon blade would shatter under their heat treat process. Goin on what ColdOne said about the 10 hour, super slow cooling, that's some pretty hardcore annealing and would make the steel pearlite which is possibly necessitated by the later stages of the heat treat. i can't see this happening post-hardening because you have to have a fast quench from austenite to create martensite. some quench cryogenically because there is usually some austenite left in the martensite that is unstable at room temperature that takes years to become martensitic, the cryo treatment accelerates that to a few hours. guess that could be it. still i can imagine them using a super pearlite in preparation for all the stress it will be put through in the austenite and martensite phases. once again, speaking directly from my hindquarters without a lick of scientific knowledge. all i see at every stage is an idea that brittle is bad and the Busses keep as far away from it as possible.

I'd like to see what they could do with sandvik and 5160, two medium-high carbon steels with reputations for toughness.

I'm not really sure of the role that nitrogen plays in the steel but other than that infi isn't all hat special chemically. s30v and h-1 have the same nitrogen content as infi but s30v is very high carbon and h-1 is high silicon. infi is high in neither. it has carbon levels more in line with inox and 12c27mod. if you read this whole post, you get a cookie. if you didn't you're probably better off.