Crucible CPM MagnaCut Knife Steel
Composition Analysis Graph, Equivalents And Overview

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CPM MagnaCut was designed as a rather wide range use steel, that could cover everything from heavy use blades to high performance, fine edge cutters. All that combined with high stain resistance. In Larrin's words, CPM CruWear or CPM 4V but stainless, if possible. Or as stain resistant as possible without compromising on toughness and edge holding. Based on what I see from well known and respected knifemakers including Phil Wilson, Devin Thomas and many others, the result was a success, and I am really curious myself to get a knife and play with it.

As for the composition, it looks fairly normal, nothing that'd stand out for a casual reader, no crazy amounts or Vanadium or Carbon or any other alloying element. What's fairly unusual though, it has Vanadium, Niobium and Nitrogen, and out of ~6500 alloys in the database less than 5 have that combination, and Nitrobe 77 is a different alloy having 0.1% Carbon in it. CPM MagnaCut has much more conventional 1.15% Carbon.

Max working hardness for CPM MagnaCut came out around 65HRC with cryogenic treatment, which is really high even for many carbon steels, and really high for stainless ones. Carbide structure is very fine based on the micrographs(much smaller than CPM-154, Bohler M390, etc). Very small grain is also worth mentioning. All that should provide for excellent properties, as far as knife blades are concerned. Definitely, CPM MagnaCut will be able to support high performance, thin, polished cutting edges. At lower hardness, it can handle a lot of stress and hard use too. Even at 65HRC, CPM MagnaCut matches toughness of most premium PM stainless steels at much lower 60-61HRC. In other words, I think the goal of making tough steel, with good edge stability and wear, plus high stain resistance was achieved, if not completely, then to a very significant degree.

In terms of pure edge wear resistance, CPM MagnaCut is between CPM S30V and CPM S90V steels, although that is a rather specific test and doesn't translate directly into high performance kitchen knife edge retention. I'd think at 65HRC, a chef's knife with a thin edge made out of CPM MagnaCut would fare far better than either of those two, but again, specific use, specific edge geometry, etc.

At 10.5% Chromium CPM MagnaCut is far more stain resistant than the number might suggest. I've mentioned in ZDP-189 knife reviews few times, just the % of Cr isn't everything, it's the free chromium combined with other factors that counts, and 3% C in ZDP-189 doesn't leave much of it, while CPM MagnaCut is more stain resistant that most stainless knife steels, outperforming even CPM 20CV, which also has 20% Cr. In saltwater tests CPM MagnaCut fared better than many well established, officially stainless steels like CPM-154, CPM S30V, CPM S35V, Takefu SG2, etc. Overall, CPM MagnaCut between CPM 20CV and Vanax in terms of corrosion resistance.

Summary: CPM MagnaCut is a very interesting alloy and I'm looking forward getting one or two different style/use knives made out of it.

Manufacturing Technology - CPM

Country - United States(US)

Known Aliases:
Crucible - MagnaCut, Crucible - CPM-MagnaCut