I'm no expert, but D2 is a pretty good in between as a "Tool Steel", when it comes to Carbon verses Stainless. But it does appear to be a little more brittle that Carbon, and not as rust resistant as Stainless. I have a D2 folder and I do have to watch it for oxidation, and I'm a bit paranoid as to it's lateral strength. INFI is certainly a step up from D2 and from my understanding is also classified as a Tool Steel as well, that's probably why you don't see much use by Busse kin these days. INFI has better lateral strength and better rust resistance too, in my experience anyway. <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />