Bohler M390 Steel
Bohler M390 stainless steel is one of the recent wave of “super steels” heralded by knife makers all over the world. It has characteristics of high hardness and excellent corrosion resistance. This means you’re going to get a very fine edge that retains it sharpness even through hard use, with little to no patina. Introduced and manufactured by Bohler-Uddeholm, M390 is a powdered steel utilizing 3rd generation technology. In industrial applications, it is often used in screws, barrels, and in injection molding. Bohler’s specifications claim a Rockwell hardness of 60 – 62HRC, putting it in the higher echelon of stainless knife steels. M390 is called a “micro clean” steel and takes a mirror finish very well. It has minimal dimensional changes and is very resistant to vibrations and mechanical shock. The chemical makeup is as follows:
- Iron – 71.5%
- Carbon – 1.9%
- Silicon – 0.7%
- Manganese – 0.3%
- Chromium – 20%
- Molybdenum – 1%
- Vanadium – 4%
- Tungsten 0.6%
Bohler M390 is almost identical to Latrobe DuraTech 20CV stainless steel. The corrosion resistance is superior to 420C stainless and it has twice the cutting edge retention. This does make it more difficult to sharpen, though not as difficult as S90V, a close cousin. The reason for this is the fine grain size, small carbides, and superior cleanliness of the powder metallurgy (PM) microstructure.
Favorites using Bohler M390 Stainless Steel
My favorite knife utilizing Bohler M390 Steel is the Steel Will Knives Cutjack Urban Flipper Knife. It has a 3.5″ satin-finish drop point blade that is 0.12″ thick. The excellent cutting ability is due to the high flat grind on the blade. The handle scales are black G-10 Micarta. Ergonomics of the Cutjack are just incredible. There is a finger groove on the handle that matches a choil just beyond it. This gives you the ability to lock into the choil and the finger groove at the same time, giving you unparalleled control and stability. The flipper, combined with the blades ball bearings allow a one-handed opening with just a slight flick of the wrist. It has a rock-solid lock up and zero sticking. A reversible, tip-up pocket clip completes the Cutjack Urban model’s design. This version of the Cutjack features an extended tang that curves beautifully into a cutout where a lanyard can be attached. Steel Will is an American company with the knives being made in Italy. Each Cutjack Urban model is boxed and individually serial numbered for the serious collector.
Bohler M390 is undoubtedly in a class all its own, being almost as corrosion resistant as H1. While the hard blade will require some owners to use a bit more elbow grease to sharpen than other stainless steels, the blade will keep that edge long after others have failed. Many bladesmiths and large knife making companies are utilizing M390 more and more thanks to these characteristics. Some online forums have even hailed this as the “holy grail” of knife steel. The truth is, as always, the perfect knife steel is the one used in the knife you choose to carry.