We independently evaluate all recommended products and services. Any products or services put forward appear in no particular order. If you click on links we provide, we may receive compensation.
M390 is a stainless powder steel for readers who want a wear-resistant cutting edge and relatively straightforward rust care. It is a good fit for repeated slicing, though sharpening takes more patience than with simpler steels. The useful question is whether that balance suits your cutting and the knife you are considering.
What Is Böhler M390?
M390 Microclean is Böhler's powder metallurgy stainless steel, originally developed for demanding industrial applications before becoming familiar in knives. Its close counterparts include CPM 20CV and CTS 204P. M390MK is a separately named variant; this profile covers standard M390.
Performance Ratings
For the science, we turn to Dr. Larrin Thomas of Knife Steel Nerds, who has kindly allowed us to share his ratings here.
| Property | Böhler M390 |
|---|---|
| Abrasive edge retention | |
| Toughness | |
| Corrosion resistance |
Heat treatment, hardness and geometry affect actual knives.
Explore Böhler M390’s Tradeoffs
Choose a steel above to highlight its position and see all three exact ratings below. The full map fits your screen.
Stainless
Böhler M390
- Abrasive edge retention
- 6.5
- Toughness
- 3.5
- Corrosion resistance
- 9
Same position; corrosion ratings may differ:
All 48 rated materials. Numbers group steels at identical coordinates; colors describe stainless classification, not corrosion scores. Neither direction means a universally better knife.
Böhler M390’s ratings are shown above. Enable JavaScript to select another steel, or browse the full ratings table.
Where M390 Makes Sense
M390's abrasive edge-retention rating is 6.5, paired with a corrosion rating of 9. That combination is appealing for a pocket knife that sees frequent slicing and occasional moisture. It does not make the blade immune to rust, but it offers more corrosion resistance in this framework than S30V or S90V.
Edge retention is only part of a pleasant cut. A thin, well-shaped blade can pass through cardboard more easily than a thicker blade, even when both use M390. Treat the steel as one part of the knife's design.
The Tradeoff: Toughness
With a toughness rating of 3.5, M390 favors wear resistance over resistance to fracture. Use it for cutting rather than levering or twisting through stubborn material. For work where chips are a recurring problem, a tougher steel may be a better fit, even if it needs sharpening sooner.
Compare M390 vs MagnaCut in the comparison tool to see their ratings side by side.
Sharpening and Rust Care
Diamond or cubic boron nitride (CBN) abrasives make sense for working with M390's hard carbides. Keep the bevel consistent and start with an abrasive coarse enough for the job; a fine finishing stone is slow at removing a chip. Regular touch-ups help keep maintenance manageable.
Clean residue from the blade and dry the knife after use. Stainless steel still needs some care, particularly around salt, acids and trapped moisture. The pivot and other parts may also need attention even when the blade looks clean.
Choosing an M390 Knife
Look for a blade shape, handle and carry size that suit your use, then consider the maker's heat-treatment information. A premium steel name cannot compensate for a poor grind. If the choice is between M390 and 20CV, their shared ratings give you good reason to let the rest of the knife decide. Our knife steel guide puts both in context.
Compare M390 vs 20CV in the comparison tool to see their ratings side by side.
Composition
Our steel composition guide explains what the elements do and how to read these values.
Böhler M390: Böhler average composition, mass %; selected elements, not a batch analysis. Böhler: M390 MICROCLEAN.
| Element | Böhler M390 |
|---|---|
| Carbon (C) | 1.9% |
| Silicon (Si) | 0.7% |
| Manganese (Mn) | 0.3% |
| Chromium (Cr) | 20% |
| Molybdenum (Mo) | 1% |
| Vanadium (V) | 4% |
| Tungsten (W) | 0.6% |
