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.
M398 is a stainless powder steel aimed at high abrasive wear resistance. It offers more edge retention than M390 in Dr. Thomas’s ratings, with a lower toughness rating and somewhat lower corrosion resistance. It makes the most sense when long sessions of controlled slicing are a real part of your use.
What Is Böhler M398 Microclean?
M398 Microclean is Böhler's powder metallurgy stainless grade developed for demanding wear applications. It has more carbon and vanadium than M390 in its specification, but it is its own alloy. The newer name does not mean it improves every useful knife property at once.
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 M398 |
|---|---|
| Abrasive edge retention | |
| Toughness | |
| Corrosion resistance |
Heat treatment, hardness and geometry affect actual knives.
Explore Böhler M398’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 M398
- Abrasive edge retention
- 9
- Toughness
- 2.5
- Corrosion resistance
- 8
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 M398’s ratings are shown above. Enable JavaScript to select another steel, or browse the full ratings table.
Where M398 Offers More Edge Retention
M398 scores 9 for abrasive edge retention, compared with M390 at 6.5. That gives it a clear wear-focused role for repeated slicing of abrasive materials. Thomas's published testing examines that gain alongside the cost in toughness.
The rating does not predict a fixed number of cuts or sharpening sessions. Material, edge geometry and heat treatment still affect the result. For light use, a knife that carries comfortably and cuts efficiently may be more rewarding than extra wear resistance you rarely need.
Toughness Is the Main Compromise
Its toughness rating is 2.5, below M390's 3.5. M398 is therefore better approached as a slicing choice than as a way to prevent edge damage. Choose a supportive edge angle for the work and take care around hard objects. If chips are a recurring problem, prioritize a tougher steel rather than simply moving farther toward wear resistance.
Sharpening and Rust Care
Diamond or cubic boron nitride (CBN) abrasives are useful for sharpening M398. Use a grit suited to the repair or touch-up, keep the angle consistent and check that the burr is removed. High abrasive wear resistance is relevant to sharpening, but treatment and deburring also affect how the job goes.
M398 scores 8 for corrosion resistance. It is stainless, yet cleaning and drying remain worthwhile after wet use. That score is below M390's 9, another reason to think of M398 as a different balance rather than an across-the-board replacement.
Should You Choose M398 over M390?
Consider M398 when abrasive edge life is a priority and you are comfortable with its toughness tradeoff. If you want a more moderate balance, M390 remains a reasonable choice. Compare the actual knives, including grind, heat treatment and price, when weighing the value of the higher wear rating. Our knife steel guide puts those tradeoffs side by side.
The M390 profile takes a closer look at the tougher, more corrosion-resistant alternative.
Composition
Our steel composition guide explains what the elements do and how to read these values.
Böhler M398: Böhler average M398 Microclean chemistry. Böhler M398 Microclean.
| Element | Böhler M398 |
|---|---|
| Carbon (C) | 2.7% |
| Chromium (Cr) | 20% |
| Vanadium (V) | 7.2% |
| Silicon (Si) | 0.5% |
| Manganese (Mn) | 0.5% |
| Molybdenum (Mo) | 1% |
| Tungsten (W) | 0.7% |
