You can find the composition on the Fallkniven or Spyderco websites. It is a fine-grained stainless containing vanadium. It is tougher than some stainless and is easy to sharpen to a razor edge. I like it a lot. It is a Japanese alloy. It is somewhat similar to AUS-10. I think of it as sort of an upgrade from AUS-8. It has that same ability to easily take a true razor edge, but it is harder.