Specification 1. Alloy tool steel which offers good machineability 2. Excellent polished finish for large section 3. Supplied in the hardened and tempered condition ready for machining 4. In this condition it gives excellent wear resistance. Application 1.Ideally suited for the production of plastic moulds. 2.Die holders, zinc die casting dies, backers, bolsters and injection moulds 3. Shafts, rails and wear strips. Chemical composition C Si Mn P S Cr Mo 0.28~0.40 0.20~0.80 0.60~1.00 â?¤0.030 â?¤0.030 1.40~2.00 0.30~0.55 Similar grade GB AISI/ASTM DIN JIS 3Cr2Mo P20 1.2311 SCM4