Hitachi Super Blue Vs CPM M4

[Thrustus]

Is there much difference between the make up and performance between these two carbon steels?

 

[A.P.F.]

Both are fine steel, but M4 is very hard to beat as a non-stainless.

 

[The Mastiff]

Both are very different steels. They are both excellent performers at what they do. They both have a bite to the edges. M4 is tougher, and has more long term wear resistance due to the carbides.

Super blue takes finer edges IMO, but also has a great bite to it. It's used in high end Japanese chefs knives whereas M4 is used in industry type cutters that need a combination of wear resistance, toughness, and an ability to work at higher speeds/ high temps. That is called "red hardness".

They are both not stainless steels but CPM M4 does a bit better at holding off the stains and rust.

I have both in folders and I'm glad I don't have to pick between them. As far as I know Spyderco is the only company ever to use Super Blue in a folder, so they are rare beasts indeed. Sal picked a great heat treat for the super blue and it performs excellently in the Spyderco Caly 3.5 folders, and an earlier mule.

A lot of us hope to see more of both, but especially Super Blue as it is so rare.

Joe