1. CPM S90V

Crucible's CPM S90V steel has the greatest wear resistance and edge retention. You might think it has a very high carbon content, but the secret here is a lot of vanadium, about three times 

the content of Elmax or S30V. Yes, it is ridiculously expensive and requires a lot of patience to sharpen, but there is really no other steel that can resist abrasion better than CPM S90V. The most 

popular CPM S90V blade is Benchmade (butterfly knife) 940-1, which has excellent performance. There is also a new emerging competition that is about to sweep the market, that is S110V...

2. M390

M390 is a super steel currently on sale, produced by Bohler-Uddeholm. (It is a merger of Bohler, Austria and Uddeholm, Sweden). It uses third-generation powder metal technology, and knife 

making requires excellent corrosion resistance and very high hardness to ensure wear resistance. Chromium, molybdenum, vanadium, and tungsten are added for increased sharpness and 

superior edge retention. Unlike ZDP-189, most of the carbides are formed from vanadium and molybdenum, leaving only free chromium for corrosion resistance. M390 hardens to 60-62HRC. 

Bohler calls this steel "Microclean" and it can be polished to a mirror finish. It is moderately difficult to sharpen, but not as laborious as S90V. The Benchmade 581 Barrage is an excellent 

example of M390 at its best.

3. ZDP-189

ZDP-189, made by Hitachi, is another new super steel that contains a lot of carbon and chromium, making it incredibly hard. ZDP-189 hardens to about 64HRC, but some knife manufacturers 

can make it as hard as 66HRC. Of course, with this super hardness, you can achieve excellent edge retention, but at the cost of increased grinding difficulty. The chromium content is about 

20%, do you think it can be free from corrosion? Not really. A lot of the carbon in ZDP-189 actually pairs up with the chromium to form carbides, so there's no free chromium to fight 

corrosion. So while it's harder and more wear-resistant than S30V, it's also more susceptible to corrosion. Spyderco's dragonfly 2 is a good example.

4. Elmax

European company Uddeholm makes Elmax, a high-chromium-vanadium-molybdenum alloy powdered steel that's extremely wear-resistant and corrosion-resistant. Elmax is stainless steel, 

but behaves like carbon steel in some ways. It has excellent edge holding and is relatively easy to sharpen, while also having good rust resistance. Is this the most well-rounded knife steel? 

Maybe. It's great to see that Bohler-Uddeholm is now a threat to Crucible. The ZT rexford 0801 is an example of an excellent Elmax blade.

5. CPM 20CV

CPM 20CV is a remake of Bohler's popular M390. Craftsman imitating CTS-204P was also affected. As a powder metallurgy tool steel, it combines excellent wear resistance and edge retention, 

plus its high chromium content makes it highly corrosion-resistant. It's still fairly new on the market, but manufacturers like Benchmade have already used CPM-20V to create new knife 

models like their 556-1 Griptilian. In fact, Benchmade claims that their M390 is slightly tougher, but the 20CV has better edge retention.