AISI M3 High-Vanadium High-Speed Steel
AISI M3 — high-V HSS (2.75–3.25 % V), HRC 64–66. Compare with M2, M4, M35 for highly abrasive cutting tools.
AISI M3 (UNS T11313) is a high-V high-speed steel available in two compositions: Class 1 (1.0 % C, 2.75 % V) and Class 2 (1.2 % C, 3.25 % V). Hardened to HRC 64–66, the high vanadium content produces a large VC carbide population that gives the highest abrasive wear resistance in the standard M-series — at the cost of grindability.
Standard composition: C 1.00–1.10 % (C1) / 1.15–1.25 % (C2), Cr 3.75–4.50 %, Mo 4.75–6.50 %, W 5.00–6.75 %, V 2.25–3.00 % (C1) / 2.75–3.75 % (C2), Mn ≤ 0.40 %, Si ≤ 0.50 %, balance Fe
Hardness: Annealed HB 217–248; hardened HRC 63–66
Heat treatment: Austenitise 1,190–1,220 °C, oil or salt quench, double temper 540–565 °C
Properties: Higher V than M2 for better wear resistance. M3C2 has the highest V in the M-series. Toughness lower than M2. Used where wear dominates over impact.
Applications: Slitter blades for abrasive composites, reamers, broaches, form tools.
Cross-reference: ≈ DIN 1.3344 (M3C2 close to M4).
See also.
