I am skeptical of M390 due to the high chromium content. It seems completely counter-intuitive that such a high-chromium steel would not be a bit lackadaisical in cutting.

Anyone have some good end-user comparisons of this steel? Due to the fact it is 'popular for use in surgical instruments', it sounds like it might perform best with a high-polish edge even though high-chromium steels seem to typically perform better with a rough micro-serrated edge from a somewhat coarse diamond sharpener.

The product information about this steel runs completely opposite of what I would expect in performance. I'd like to know more about the heat treat and Rc. I need to get my hands on some and test it out.

I am not sure what you are implying about the chromium content of the steel. My understanding is that chromium has two functions, carbide formation and corrosion resistance. Carbides contribute to the wear resistance of the steel. In order to form carbides a non ferrous metal combines with carbon. Chromium is not the only carbide forming agent, and other carbide agents can allow for more free chromium.

according to the chemistry, M390 should be an incredible steel. The only possibility for fault I can find would be from a poor heat treatment. Heat treatment for such a complex steel can be rather challenging.

I'm sure I missed a lot of detail and such.

I am not a metallurgist - just a knife-user. My m390-equipped 755 MPR has been my 24/7 EDC for most of the last 20+ months. In that time, it has been resharpened several times on my Sharpmaker, stopping with the white file's edges - and armhair-popping sharpness. I would rate it's edge keeping as at least as good as my previous favorite S30V - and resharpening as decidedly easier.

My uses for this knife are varied - from opening mail, blister-packed products, cutting my lunch to size, some whittling, slicing coupons from adverts in the checkout line, and even reducing cardboard boxes to waste. It's life is varied - and I haven't always been kind or even considerate to it. The tip is still intact, there has been no edge chipping or rolling. I also have a 581 and 480-1, and, thanks to Mrs. Santa, another 755, all in m390, that I am much more reserved in their use - and I have thoroughly enjoyed them, too.

Stainz

I can fully back up Stainz in praising M390. I too have a 581 Barrage (BK version), it is the best edge I own, and I have an extensive variety of Case, Buck, and now two Benchmades (The 581/M390 and a 943/S30V). My only complaint with M390 is the extra time required to sharpen, even with diamond hones. I studied metallurgy a few years ago at the college level and have more than a wotking knowledge of the hardening process. I suggest you visit the Bohler site where there is a very detailed explaination of M390 and the heat treating process. You can jump to it through the Benchmade site under steels. By the end result of the 581BK that I have, I am confident that Benchmade has nailed the tempering process on this one.

Jim Lucier

I do not have much time with m390, but I can tell it cuts way better than s30v, 154cm, etc. Its smooth and effortless on my m390 compared to other steels

I have a few M390 fixed blades. I found them very easy to sharpen. I would call myself a rookie at sharpening and I didn't even break a sweat bringing M390 back to a very sharp edge.

Ya, I think its the nicest stainless steel I've used. It seems a little more forgiving than S90V when you go to sharpen them. It sharpens easier than D2 (which is just barely considered a stainless).

Personally, I still prefer the carbon tool steels for folding knives, but if I need stainless, M390 is it for me.

i consider m390 to be as good as it gets currently. gets as sharp as m2/m4, as stainless as 154cm, holds an edge as well as s90v. in fact a little better because it holds that extreme high initial sharpness better. it's also easier to sharpen for me as it doesn't form as much of a burr. i'd love a rift in this steel some day