MagnaMax offers significantly better edge retention and comparable (or slightly better) toughness than CPM-20CV, while matching its excellent corrosion resistance. For users who want maximum cutting performance without sacrificing durability or rust resistance, MagnaMax is the superior steel.
Head-to-Head Comparison
| Property | MagnaMax | CPM-20CV |
|---|---|---|
| Edge Retention | Excellent – on par with K390; clearly better than CPM-20CV | Very good – similar to M390; outperformed by newer high-vanadium steels |
| Toughness | High – comparable to K390; suitable for hard-use knives | Good – better than M390/S90V, but lower than MagnaMax |
| Corrosion Resistance | Exceptional – zero rust in 1% saltwater test | Excellent – among the best stainless steels; very close to MagnaMax |
| Carbide Structure | ～16% fine vanadium-niobium carbides; no coarse Cr-carbides | ～15–18% vanadium & chromium carbides; some are relatively large |
| Ease of Sharpening | Challenging but manageable (similar to K390) | Moderate to difficult – easier than S90V, harder than S35VN |
| Typical Use | Tactical, outdoor, chef’s, marine knives | High-end EDC, premium folders (e.g., Benchmade, Spyderco) |
Key Insights
🔹 Edge Retention: MagnaMax Pulls Ahead
- CPM-20CV (Carpenter’s version of Bohler M390) is known for strong all-around performance, but its edge retention is outpaced by modern ultra-high-vanadium steels.
- The article states that MagnaMax matches K390 in CATRA testing—a benchmark that CPM-20CV does not reach. Independent tests consistently rank CPM-20CV below K390, S110V, and now MagnaMax in wear resistance.
🔹 Toughness: MagnaMax Has the Edge
- While CPM-20CV has better toughness than M390 (thanks to CPM processing), it still contains large chromium-rich carbides that can act as crack initiation sites.
- MagnaMax avoids chromium carbides entirely, using only fine vanadium-niobium carbides. This results in higher fracture toughness—critical for thin blades, batoning, or impact tasks.
🔹 Corrosion Resistance: Nearly Equal—But MagnaMax May Win
- Both steels contain ～20% chromium and are considered highly corrosion-resistant.
- However, in MagnaMax, more chromium remains in solid solution (not tied up in carbides), enhancing passive film formation.
- In the Knife Steel Nerds saltwater test, MagnaMax showed zero rust—a result CPM-20CV usually achieves, but not always under prolonged exposure (some users report minor spotting in harsh conditions).
- Thus, MagnaMax likely has a slight edge in real-world corrosion resistance.
🔹 Metallurgical Innovation
- CPM-20CV: A refined version of M390—excellent for its era, but based on older design principles.
- MagnaMax: Built on the MagnaCut platform, which rethinks stainless steel design by eliminating detrimental chromium carbides and optimizing carbide type/size via niobium additions. It represents a next-generation approach.
As the article notes:
“MagnaMax delivers a combination of properties previously unattainable in a single stainless steel.”
When Might CPM-20CV Still Be Preferred?
- If you prioritize proven reliability and wide availability (many flagship knives use it).
- If you want easier sharpening than S110V but don’t need extreme edge retention.
- If your use case is light-to-moderate EDC where CPM-20CV’s performance is more than sufficient.
But if you want the highest possible performance in a stainless steel, MagnaMax is the new leader.
Final Verdict
✅ Edge Retention: MagnaMax > CPM-20CV
✅ Toughness: MagnaMax ≥ CPM-20CV
✅ Corrosion Resistance: MagnaMax ≈ or > CPM-20CV
✅ Overall Performance: MagnaMax is the more advanced steel
✅ Toughness: MagnaMax ≥ CPM-20CV
✅ Corrosion Resistance: MagnaMax ≈ or > CPM-20CV
✅ Overall Performance: MagnaMax is the more advanced steel
Conclusion: CPM-20CV remains an excellent, well-balanced steel—but MagnaMax surpasses it in the key metric of edge retention while maintaining or improving on toughness and corrosion resistance.
For discerning users seeking the best-in-class stainless blade in 2026 and beyond, MagnaMax is the clear upgrade.
In short:
CPM-20CV was the gold standard. MagnaMax is the new platinum.
