Knife Steel: PM A11

This is a rather obscure steel offered as one of Spyderco's mule team blades (MT26). Spyerco's description follows:
Spyderco’s twenty-sixth Mule Team installment features Carpenter® Technology Corporation's Micro-Melt® A11, a particle metallurgy version of A11 tool steel. Also known as AISI A11, K294 (Böhler-Uddeholm), CPM® 10V (Crucible®), and PMA11. It is an extremely wear-resistant tool steel that is capable of achieving a high working hardness. One of the world's premier steel choices for highly wear-resistant industrial tooling, in its CPM 10V form it is also one of the favorite steels of renowned custom knifemaker and Spyderco collaborator Phil Wilson.

PMA11's alloy composition is as follows: Carbon: 2.45%, Manganese: 0.50%, Silicon: 0.90%, Chromium: 5.30%, Molybdenum: 1.30%, Vanadium: 9.50%, Sulfur 0.08%. Its large volume of hard vanadium carbides provides substantially better wear-resistance than typical high-carbon, high-chromium die steels such as D2 and D7. In knife blades, this translates to outstanding edge retention and good toughness, especially in shorter knives.

Note also that the Spyderco K2 Farid uses 10V steel.


K390 is very similar to 10V. It has small quantities of Tungsten and 2 percent Cobalt, which A11 lacks.

One person raved about K390 and said:

A combo of S110V's cuttablity, M4's toughness, super blue's patina and cru-wear's sharpenablity.
K390 has been called "M4 on steroids" and Sal from Spyderco chose K390 for the new "Police" model because it is what he wanted to carry.

Phil Wilson says:

I have been using K390 from the start ever since it was introduced by Bohler and I got some small samples to try. A bit of history is that it is the European version of CPM 10V but not the exact chemistry (about 1% less V plus small addition of a few others). That is because the CPM 10V chemistry was protected by patent at the time. If you check the K390 data sheet it claims that the bit less V gives K 390 a little boost in impact toughness. It also can be heat treated at a lower temp. than 10v. So it is pretty much the same as the A11 grade but different in a few small details. It is hard to tell the difference between CPM 10v and BU K390 in the real world in my experience. I like both grades and they are the base line (along with Vanadius 10 and K294) from which I measure wear resistance. The 5 chrome is there to make them all air hardening among other things and does not contribute much to corrosion resistance. It is going to make a killer knife in the new offering and be another classic. Phil

A11 and CPM 10V

With only 5.3 percent Chromium, these steels will rust unless cared for. I have had no problems whatsoever in the Arizona desert.

The best way to get an idea of what people think of this steel is by researching CPM 10V (or K294).

Amazingly, 10V outperforms S110V as far as edge retention.

These steels are quite difficult to work with and typically only found on custom knives.

Feedback? Questions? Drop me a line!

Tom's Knife Info / tom@mmto.org