To Jailhack:
12C27 is produced in Sweden by Sandvik, a very large hand tool and steel manufacturer. The poplarity of 12C27 in US production company is rather limited due to a lack on Sandvik's part of promoting and advertising 12C27 to the US knife market. The US knife company Benchmark (Now out of business), used 12C27 in almost all their knives. I believe 12C27 has also been used by Spyderco although I don't know in exactly which models. In Sweden, 12C27 is the #1 production knife steel. A good RC hardness for 12C27 is 57. Although the RC hardness is lower that several premium grades of stainless such as ATS-34, the heat treated grain structure of 12C27 is very fine. This allows you to get a very keen, razor sharp finished edge, and the ability to resharpen it. Therefore 12C27 will cut and and hold an edge more like a comparable steel with RC59. Note that we are using AUS-8A in the Magna and 12C27 in the Impulse knife. We chose 12C27 for the Impulse because this is the highest quality of stainless we have found that can be fine blanked. Fine blanking is essential for the Impulse in order to achieve the geometric holes in the blade.
Thank you for your interest.
Outdoor Edge Cutlery Corp.