Magnacut
MagnaCut is a modern powder-metallurgy stainless steel designed specifically for knife applications by metallurgist Dr. Larrin Thomas. Released in 2021, it set out to solve a long-standing tradeoff in knife steel design: traditional stainless steels typically sacrifice either toughness or corrosion resistance to reach high hardness and edge retention. MagnaCut keeps nearly all of its chromium in solid solution rather than locking it into large, brittle carbides, which lets it deliver strong toughness, edge retention, and corrosion resistance at the same time, a combination few other steels can match.
MagnaCut FAQ
What hardness does MagnaCut reach?
With Crucible’s recommended heat treatment, MagnaCut typically reaches 61-62.5 HRC, and up to 63-65+ HRC with an added cryogenic treatment after the quench. See the heat treat details further down this page for the full recipe.
Is MagnaCut worth the extra cost over CPM 20CV or CPM S45VN?
For most users, yes, if toughness and chip resistance are a priority. MagnaCut is noticeably tougher than both while matching or beating their corrosion resistance, though CPM 20CV and S45VN each hold a slight edge-retention advantage. See the full breakdowns: MagnaCut vs CPM 20CV and MagnaCut vs CPM S45VN.
Does MagnaCut rust?
Not meaningfully more than other high-chromium stainless steels. MagnaCut’s corrosion resistance is on par with the best modern stainless knife steels, so normal care (wiping down and drying after wet use) is enough to keep it rust-free.
Is MagnaCut hard to sharpen?
It is more demanding than simple carbon steels, but it is considered one of the more sharpenable premium stainless steels for its performance class, since most of its chromium stays out of large carbides. Diamond or CBN abrasives are recommended for maintaining an edge once hardened. See the full grinding and sharpening guide for belt and abrasive recommendations.
Is MagnaCut a good first knife steel to work with?
Not usually. It is a capable steel, but not the easiest to heat treat at home. It needs a foil-wrapped or controlled-atmosphere oven and precise soak temperatures to reach its full potential. New makers are often better off starting with a simpler steel like 1084 before working up to MagnaCut.
What is MagnaCut best used for?
General-purpose EDC, hunting, and kitchen knives where excellent all-around performance and a low risk of chipping both matter. See the Best Uses section further down this page for more detail.
Also known as: CPM MagnaCut, Magnacut
Composition
| Carbon (C) | 1.15% |
| Chromium (Cr) | 10.7% |
| Vanadium (V) | 4.00% |
| Molybdenum (Mo) | 2.00% |
| Niobium (Nb) | 2.00% |
| Nitrogen (N) | 0.20% |
Properties
| Property | Rating | Notes |
|---|---|---|
| Toughness | ★★★★★ | In Charpy impact testing at 62.5 HRC, MagnaCut delivers roughly 38 ft-lbs of toughness, about 40% tougher than S35VN at similar hardness, and roughly double the toughness of M390. It performs on par with tough non-stainless steels like CPM 4V and Vanadis 4 Extra. |
| Edge Retention | ★★★★☆ | CATRA edge-retention testing places MagnaCut between S35VN and S45VN, very good, though not at the extreme end occupied by steels like S90V or M390. |
| Corrosion Resistance | ★★★★★ | MagnaCut keeps its full 10.7% chromium in solid solution, giving it corrosion resistance that exceeds S35VN, S45VN, M390, and 20CV, among the best of any high-performance knife steel, approaching though not quite reaching saltwater-grade steels like Vanax or LC200N. |
| Machinability / Grinding | ★★★☆☆ | Like other vanadium-rich powder-metallurgy steels, MagnaCut is moderately demanding to grind because of hard vanadium and niobium carbides. Expect belt wear similar to or slightly higher than S35VN; ceramic or high-quality zirconia belts are recommended for stock removal. |
Heat Treatment
Recommended heat treatment from Crucible: austenitize at 2050 degrees F (1121 C) for approximately 25 minutes, then plate or oil quench, followed by tempering 2×2 hours at 350 degrees F (176 C). This typically yields 61-62.5 HRC. An optional cryogenic treatment (dry ice or liquid nitrogen) immediately after quenching can push hardness to 63-65+ HRC.
Because MagnaCut is a stainless PM steel, it should be heat treated in a foil-wrapped or controlled-atmosphere environment to prevent scale and decarburization, and requires an oven capable of holding precise soak temperatures. A dedicated quench plate system makes it much easier to control warping during the plate quench step. For the general principles behind every stage of this process, see our Complete Guide to Heat Treating Knife Steel.
Best Uses
This rare combination of toughness, edge retention, and corrosion resistance makes MagnaCut an excellent general-purpose and hard-use knife steel, well suited to EDC knives, hunting and fillet knives, and outdoor or survival blades that may see rough use in wet conditions. Browse more entries in the Knife Steel Database to compare it against other options.
Sources: Crucible Industries, CPM MagnaCut Data Sheet. Larrin Thomas, CPM MagnaCut: The Next Breakthrough in Knife Steel, Knife Steel Nerds, March 2021.