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 has higher abrasive edge retention and much greater corrosion resistance than conventional D2, while their toughness ratings are equal. Its strongest everyday benefit may be the reduced rust concern rather than the name’s premium reputation.
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 | D2 | Böhler M390 |
|---|---|---|
| Abrasive edge retention | ||
| Toughness | ||
| Corrosion resistance |
Heat treatment, hardness and geometry affect actual knives.
M390 Offers More Abrasive Wear Resistance
M390 rates 6.5 for abrasive edge retention against D2 at 5. We would favor M390 for sustained abrasive slicing when the knife designs are comparable.
The D2 here is conventional D2. A listing for CPM D2 represents a different material comparison.
Our D2 steel profile explains its properties and care in more detail.
The Toughness Score Does Not Improve
Both rate 3.5 for toughness. Moving from D2 to M390 should not be presented as a material-level solution to chipping on these figures alone.
If edge damage is the problem, examine angle, thickness and use. A more expensive blade steel is not automatically tougher.
Our M390 steel profile explains its properties and care in more detail.
M390 Makes Wet Carry Easier
M390 rates 9 for corrosion resistance and D2 rates 4.5. This is a much larger separation than the wear difference.
D2 needs more care after moisture exposure and during storage. M390 is stainless but should still be cleaned and dried.
A Useful Upgrade for Wear and Rust Care
We would prefer M390 when its extra wear and corrosion resistance justify the actual knife and price. A good D2 design can still make sense for drier use with regular maintenance.
Do not give up a suitable grip or blade shape simply to change steel. The upgrade should improve the work you actually do.
Composition
Our steel composition guide explains the elements and the differences between reported values, ranges and limits.
D2: Niagara typical composition, mass %; selected elements, not a batch analysis. Niagara Specialty Metals: D2.
Böhler M390: Böhler average composition, mass %; selected elements, not a batch analysis. Böhler: M390 MICROCLEAN.
| Element | D2 | Böhler M390 |
|---|---|---|
| Carbon (C) | 1.42% | 1.9% |
| Chromium (Cr) | 11.5% | 20% |
| Molybdenum (Mo) | 0.9% | 1% |
| Vanadium (V) | 0.8% | 4% |
| Silicon (Si) | Not listed | 0.7% |
| Manganese (Mn) | Not listed | 0.3% |
| Tungsten (W) | Not listed | 0.6% |
Compare Two Knife Steels
Sources and Update Notes
- Dr. Larrin Thomas: knife steel ratings · Property ratings; the scores describe steels rather than individual finished knives.
- Niagara Specialty Metals: D2
- Böhler: M390 MICROCLEAN
