For those who want to get wrapped around the axle on heat treating, toughness, hardness, composition, and such, there are those on this forum who can tell you how many angels can dance on the point of Dumpster Mutt. They can take you from the Iron Age to INFI. The proof is in the pudding and the eating thereof. S7 is made into SR77 by a proprietary heat treament. That is the key to its edge retention along with toughness that jackhammer steel has. I just take 'em out and use 'em for their intended purposes and give my impressions. I don't care if they do it with pixie dust, differential heat treatment, sub-zero quench, or 3% unobtainium, just so it performs.