Why is high manganese steel used in these ninjato blades?
Updated Feb 2026
High manganese steel offers a practical balance of hardness and affordability that suits collectible-grade swords well. Its carbon content, typically between 0.60% and 0.90%, allows the blade to be heat-treated to a Rockwell hardness in the low-to-mid 50s, which is sufficient to maintain a stable edge profile and resist surface deformation during handling or display. Manganese as an alloying element also improves tensile strength and wear resistance compared to plain carbon steel at the same price tier. For collectors who want a full-tang blade that looks and feels substantial without stepping up to folded tamahagane or T10 tool steel, high manganese is one of the most reliable options on the market.