1. Roberts G, Cary R: “Tool Steels”, 5th edn, 251–290; 1998, Materials Park, OH, ASM.
2. Hoyle G: ‘High speed steels’, Vol. 1; 1988, London, Butterworths.
3. Imoto A, Barbosa CA: Proc. XXXV Cong. Anual da ABM, 117; 1980, Sao Paulo, ABM.
4. Fracture toughness of M2 and H13 alloy tool steels
5. The effect of retained austenite on the fracture toughness of high-speed steels