Steel matchup
MagnaCut and CPM 20CV, compared on the five things that decide a blade: toughness, edge retention, corrosion, heat treat and how each one grinds.
A powder-metallurgy stainless steel balancing high toughness, strong edge retention, and excellent corrosion resistance, widely regarded as one of the most well-rounded modern knife steels.
A top-tier powder-metallurgy stainless steel, chemically near-identical to M390, prized for exceptional edge retention and excellent corrosion resistance in premium EDC and outdoor knives.
Dimension by dimension
Each steel's own note, its score out of five, and what separates the two in that one column. The higher score in a row is marked in purple.
| Dimension | MagnaCut | CPM 20CV | What separates them |
|---|---|---|---|
| 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. | The tradeoff for its extreme wear resistance: hardened to 60+ Rc with a heavy carbide load, it is more prone to micro-chipping than tougher steels like CPM 3V or CruWear. | This is where the two steels really diverge. MagnaCut was purpose-built by Larrin Thomas to solve the chipping problems common to high-vanadium steels like 20CV, and it shows: MagnaCut is significantly tougher and far more resistant to micro-chipping at the edge, especially at typical working hardness. |
| 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. | Exceptional wear resistance from a very heavy chromium and vanadium carbide load, among the best edge retention available in a knife steel. | CPM 20CV holds a slight edge here thanks to its heavier chromium and vanadium carbide load, giving it marginally better raw wear resistance. The gap is real but smaller than the toughness gap runs the other way, so most users will not notice a dramatic difference in sharpening interval. |
| 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. | 20% chromium gives it excellent, top-tier stainless performance, a strong choice for wet, humid, or marine environments. | Essentially tied. Both use roughly 20% chromium and are considered top-tier for stainless corrosion resistance, suitable for wet, humid, or marine environments without issue. |
| Heat treat | Recommended heat treatment from Crucible: austenitize at 2050 degrees F (1121 C) for approximately 25 minutes, then plate or oil quench, followed by tempering 2x2 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. | A validated recipe from independent toughness testing: austenitize at 2140 F, plate quench, apply a cryogenic treatment, then temper at 365 F. Most knifemakers target the 60-62 Rc range. Because this steel demands precise, high-temperature equipment and a controlled quench, it is best suited to makers with a programmable oven or a professional heat-treating service. | MagnaCut was specifically designed to be more forgiving to heat treat, reaching excellent properties with equipment accessible to small shops. CPM 20CV demands a higher, more precise austenitizing temperature (around 2140 F) and benefits heavily from a professional-grade oven and controlled quench, making it less forgiving for makers without commercial equipment. |
| 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. | Demanding to grind and sharpen; typically requires diamond or CBN abrasives to sharpen efficiently once fully hardened, more challenging than most other steels in this database. | MagnaCut is somewhat easier to grind and sharpen than CPM 20CV, though both are demanding compared to simpler steels and benefit from diamond or CBN sharpening abrasives once fully hardened. |
Best use
MagnaCut
Choose MagnaCut for general-purpose EDC, hunting, and kitchen knives where you want excellent all-around performance with a low risk of chipping, and where working with a small shop heat-treat setup matters.
Open the MagnaCut referenceCPM 20CV
Choose CPM 20CV when maximum edge retention is the top priority, corrosion resistance still matters, and you have access to precise, professional-grade heat treating.
Open the CPM 20CV reference
The long answer
MagnaCut and CPM 20CV both sit near the top of the premium stainless steel world, but they were designed with different priorities. MagnaCut was engineered specifically to fix the toughness weaknesses of high-carbide steels like 20CV and M390, while CPM 20CV leans further into raw wear resistance. Here is how the two actually compare for knifemaking.
Keep comparing
Keep reading
CPM 20CV sits alongside CPM S30V and CPM M4 among the more demanding steels in this database to grind and sharpen. The same heavy chromium-vanadium…
MagnaCut is one of the more demanding steels to grind on a 2×72 platform. Its heavy carbide load, the same chemistry that gives it excellent toughness and…
Every knife steel is iron plus a specific recipe of other elements, and each of those elements pulls the steel’s behavior in a particular direction…
Same bench
Whichever steel wins, the grind is only as flat as the platen behind it. I machine the parts, hand-assemble, track and test Torus grinders in Sterling, Illinois.
Current dual-axis platform with a fiber-laser-cut 6061 chassis and single-knob tracking.
Current dual-axis platform with a steel chassis, more mass and less vibration.
Prior-design aluminum chassis, 90-degree tilt and 1.5-inch tooling arms.
One-man shop
Tell me what the blade is for and how you heat treat, and I will tell you which of these I would put on the bench — including when the answer is neither.
