CPM MagnaMax - Stainless Steel Flat Bars

CPM MagnaMax - Stainless Steel Flat Bars

MagnaMax is supplied hot rolled and annealed, like other premium powder-metallurgy blade steels in its class — soft and workable in the annealed state for cutting, grinding, drilling, and filing, with some thickness variance batch to batch.

MagnaMax is the steel Larrin Thomas first conceived back in 2019, while developing MagnaCut, as a higher-wear-resistance companion he originally called "stainless 10V." It's built to match the toughness and edge retention of non-stainless grades like K390, Vanadis 8, and CPM-10V, while keeping the same excellent corrosion resistance that made MagnaCut famous. It isn't meant to replace MagnaCut so much as sit alongside it as the higher-edge-retention sibling in the same steel family.

MagnaMax was officially introduced in 2025 and went on sale through Niagara Specialty Metals' online store starting May 1, 2026. Production has been split across companies since Crucible's closure: powder atomization is now handled by Erasteel or Carpenter Technology, while NSM handles final rolling and distribution of the sheet steel used by knifemakers. 

Composition

A full datasheet hasn't been publicly released yet. What's known: MagnaMax uses the same general compositional approach as MagnaCut, but with increased carbon, niobium, and vanadium to boost wear resistance. The result is roughly double the hard carbide volume of MagnaCut — about 16%, versus MagnaCut's 8% — made up primarily of fine vanadium and niobium carbides rather than larger chromium carbides. Thomas's design approach was that smaller carbides allow more carbide volume to be packed in while keeping toughness at practical levels.

Performance Characteristics

• Toughness — MagnaMax trades some toughness for its wear-resistance gains, but matches the toughness of high-end stainless grades like CPM S35VN and CPM 154, and independent testing found its toughness very similar to non-stainless tool steels K390 and Vanadis 8. It's still roughly twice as tough as M390, just not in the same class as MagnaCut. 
• Edge retention — This is where MagnaMax pulls ahead of MagnaCut. With roughly double MagnaCut's carbide volume, edge life is drastically improved, and the difference shows up clearly when cutting abrasive materials like cardboard or rope. 
• Corrosion resistance — MagnaMax shares the same high corrosion resistance as MagnaCut, making it suitable for the same marine, outdoor, and kitchen applications. 

Heat Treatment

Based on Larrin Thomas's published testing (not yet a finalized factory datasheet):

• Best hardness-toughness balance generally comes from austenitizing at 2150-2200°F (1175-1230°C) with tempering at 350-450°F (175-230°C). Knife Steel Nerds
• For lower hardness with maximum toughness, 2100°F (1150°C) paired with a 450°F (230°C) temper performed best. 
• For maximum hardness, use 2150-2250°F (1175-1230°C) with the minimum 300°F (150°C) temper.
• Thomas has also noted that large-scale industrial heat treating (vacuum furnace, pressurized gas quench) differs somewhat from the small-furnace/plate-quench process used in his own testing, so results may vary if you're sending blades out versus heat treating in-house. 
  Our own heat treating service is capable of doing the small batch heat treating that best services this steel. 

Recommended Working Hardness

MagnaMax typically heat-treats to 63-65 HRC — noticeably higher than MagnaCut's usual 60-62 HRC range, consistent with its higher carbide volume and wear-resistance focus.