· KAIPU Engineering · materials-encyclopedia · 1 min read
AISI T15 Cobalt-Bearing Tungsten Super High-Speed Steel
Materials encyclopedia entry for T15.
AISI T15 Cobalt-Bearing Tungsten Super 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 1.50–1.60 %, Cr 3.75–5.00 %, W 11.75–13.00 %, V 4.50–5.25 %, Co 4.75–5.25 %, Mo ≤ 1.00 %, Mn ≤ 0.40 %, Si ≤ 0.50 %, balance Fe
Hardness: Annealed HB 241–277; hardened HRC 65–68
Heat treatment: Austenitise 1,235–1,260 °C, oil or salt quench, double temper 540–565 °C
Properties: The 12 % W + 5 % V + 5 % Co gives exceptional hot hardness and wear resistance. Hardness up to HRC 68. Toughness lower than M2. Used for the most demanding cutting applications.
Applications: High-performance slitter blades, hard-to-machine aerospace alloys, advanced die-casting tooling.
Cross-reference: ≈ JIS SKH10, DIN 1.3202, GB W12Cr4V5Co5, BS BT15.
See also: D2 vs SKD11 comparison, Material Grade Converter, The KAIPU 5-Factor Blade Selection Framework.