CPM-MagnaCut: The Steel That Changed the Conversation

CPM-MagnaCut was developed by metallurgist Larrin Thomas and introduced by Crucible Industries in 2021. It isn't an incremental update — it's a formula that was specifically designed to break a longstanding tradeoff in knife steel: the fact that corrosion resistance and toughness had always been inversely related to each other at high hardness.

The mechanism is deliberate carbide engineering. MagnaCut uses a chromium-nitrogen balance that keeps chromium in solution for corrosion resistance while using vanadium and niobium carbides for cutting performance — rather than relying on chromium carbides, which consume the chromium that would otherwise protect against rust. The result: corrosion resistance in the H1/LC200N tier (steels previously used only for diving knives) with edge retention that exceeds S35VN and toughness that competes with CPM-3V.

Composition

Carbon 1.15% · Chromium 10.70% · Vanadium 4.00% · Niobium 2.00% · Molybdenum 2.00% · Nitrogen 0.20%. The lower chromium percentage (relative to S35VN's 14%) is counterintuitive for a steel with better corrosion resistance — but it's kept in solution rather than locked up in carbides, which is what makes it available to resist oxidation at the surface level.

What it's actually like to carry

MagnaCut at 63–65 HRC has edge retention noticeably beyond S35VN in standardized CATRA testing — roughly 20–30% more cuts before measurable dulling in most independent reports. In practical EDC terms, this means weeks rather than days before a maintenance strop is warranted under typical use.

The real differentiator is corrosion resistance. You can leave a MagnaCut blade wet — genuinely wet, not just humid — and it won't rust. This matters for coastal carry, kitchen use, outdoor and hunting applications, or simply anyone who forgets to wipe their blade before pocketing it. Previous steels with this level of corrosion resistance (H1, LC200N) achieved it by sacrificing hardness and edge retention. MagnaCut does not make that trade.

Sharpening MagnaCut requires slightly more effort than S35VN due to the harder, more refined carbide structure. Diamond stones work well. Ceramic rods are adequate for touch-ups. It's not as demanding as M390 but it's not a beginner's steel either.

The catch

Availability. MagnaCut is newer and production volume is lower than S35VN or M390. The number of production folders running it is growing year-over-year but still small relative to the overall market. Expect to pay a premium in the $150–$250 range for MagnaCut folders that would cost $75–$120 in S35VN. The Hogue Deka at $170 is currently the best value entry point.