M390 steel
M390 is a powder metallurgy stainless steel from voestalpine Bohler Edelstahl. It rates 8/10 for edge retention, 4/10 for toughness and 9/10 for corrosion resistance, and is usually hardened to 60–62 HRC.
At a glance
- Type
- Powder metallurgy stainless steels
- Hardness
- 60–62 HRC
- Maker
- voestalpine Bohler Edelstahl (Austria)
- Process
- PM
- Price tier
- Premium
- Used by
- Benchmade, Spyderco, WE Knife, Reate, Microtech, Lionsteel, Shirogorov, Kizer
- Also called
- Bohler M390 Microclean, M390
Composition
| Element | Weight % |
|---|---|
| Carbon (C) | 1.9 |
| Chromium (Cr) | 20 |
| Vanadium (V) | 4 |
| Molybdenum (Mo) | 1 |
| Tungsten (W) | 0.6 |
| Manganese (Mn) | 0.3 |
| Silicon (Si) | 0.7 |
Source: manufacturer datasheet. Nominal values; where a range is published, the midpoint is shown. Phosphorus and sulfur, where listed, are maximums.
What makes M390 behave the way it does
M390 contains 1.9% carbon, a high level that supports high hardness and a large volume of hard carbides; 20% chromium for corrosion resistance.
Its 4% vanadium forms vanadium carbides, among the hardest carbides in knife steels, which drive wear resistance and slow edge loss but also make the steel slower to sharpen; molybdenum (1%) improves hardenability and pitting resistance.
It is made by powder metallurgy: the alloy is atomised into fine powder and consolidated, which keeps the carbides small and evenly spread. That is what lets a highly alloyed steel stay tough enough for a knife blade.
20CV and CTS-204P are compositionally identical.
Equivalent and similar steels
- M390 class (same nominal composition from different mills): M390, CPM 20CV, CTS-204P
Knives in M390
| Knife | Brand | Blade | Weight | Lock | List price | Buy |
|---|---|---|---|---|---|---|
| Benchmade Narrows | Benchmade | 3.43" | 2.41 oz | AXIS lock | $525 | Blade HQ |
| Microtech Ultratech Gen IV S/E | Microtech | 3.55" | — | OTF automatic | $367 | Blade HQ |
| WE Knife Suisei | WE Knife | 3.28" | 3.55 oz | Liner lock | $350 | Blade HQ |
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How to sharpen M390
M390 is slow to sharpen (3/10). Its vanadium carbides are harder than the aluminium oxide in conventional stones, so diamond or CBN plates cut it far more efficiently. Once sharp, it needs touch-ups less often.
Compare M390 with
FAQ
Is M390 a good knife steel?
M390 is strongest in corrosion resistance (9/10) and weakest in ease of sharpening (3/10). Its average across the four ratings is 6.0/10, and it sits in the premium price tier.
Does M390 rust?
Very little. M390 rates 9/10 for corrosion resistance, among the best of any knife steel, and suits salt water and humid climates.
Is M390 hard to sharpen?
M390 is slow to sharpen (3/10). Its vanadium carbides are harder than the aluminium oxide in conventional stones, so diamond or CBN plates cut it far more efficiently. Once sharp, it needs touch-ups less often.
What hardness is M390?
Knives in M390 are usually hardened to 60–62 HRC. Makers can run it outside that range; harder means better edge retention but lower toughness.