I don't want something that will rust if you leave a fingerprint on it(some do) but definitely a step or three above 440C, which is pretty good.
I also would like to know the best company to buy from that makes knives with that steel. I'm looking for a folding pocket knife, probably assisted opening.
Go with kershaw if you want assisted opening. their sandvic steel can get scary sharp and is stainless, but its only about the level of 440C. If you have ~$150 to spend, got with Benchmade's nitrous stryker. D2 is a very tough, sharp steel, but between stainless and carbon steel in rust resistance. Other steels to look at are vg-10 (spyderco, look at their wave feature), 154cm, bg42, s30v, s60v, s90v, and the absolute best are SGPS laminated steel (Fallkniven U2), zdp-189 (spyderco again) and INFI (Busse, VERY expensive but worth it).
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