· KAIPU Engineering · materials-encyclopedia · 1 min read
AISI M3 Class 1 & Class 2 High-Speed Steel
Materials encyclopedia entry for M3.
AISI M3 Class 1 & Class 2 High-Speed Steel is a reference entry for industrial cutting tools and blades. The composition, hardness, heat treatment and application guidance are summarised below for engineering reference.
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: D2 vs SKD11 comparison, Material Grade Converter, The KAIPU 5-Factor Blade Selection Framework.