
AISI M1 Molybdenum High-Speed Steel
AISI M1 (UNS T11301) — tungsten-free Mo HSS, HRC 63–65. Compare with M2, M3, M35 for slitter blades and drills where M2 is overkill.

AISI M1 (UNS T11301) — tungsten-free Mo HSS, HRC 63–65. Compare with M2, M3, M35 for slitter blades and drills where M2 is overkill.

AISI M3 — high-V HSS (2.75–3.25 % V), HRC 64–66. Compare with M2, M4, M35 for highly abrasive cutting tools.

AISI M35 — 5 % Co M2 modification, hot hardness HRC 60 at 600 °C. Compare with M2 and M42 for high-speed slitter blades (>800 m/min).

AISI M42 (UNS T11342) — 8 % Co super HSS, HRC 65–69, hot hardness HRC 60–62 at 600 °C. Compare with M35 and T15.

AISI M50 (UNS T11350) — Cr-V-Mo HSS for bearings, HRC 64–66, low distortion. Compare with M2 for high-RPM cutting tools.

AISI D2 is a high-carbon, high-chromium cold-work tool steel widely used for industrial slitter, shear and granulator blades.