I have a bunch of BRKT A2 knives. A2 is a fine grained tool steel that is known for it's toughness, sharpness, and ease of sharpening. It holds a fine edge fairly well. It will rust if not cared for. (I speak from experience, I learn slow).
BRKT A2 steel knives (Bravo-1, Aurora, etc.) are close to un-breakable in normal (read woodslore abusive) use.