... #, 45#, 50#, 60#; Japan Standard: S20C, S25C, S35C, S45C, S55C, S60C; US Standard: AISI1020, AISI1040, AISI1045, AISI1050; urope Standard: CK15, C. 22, C45 ... , SCM420, SCM440, SNCM439, SNCM220; SACM645 USA Standard: SAE4140, SAE4130, SAE9840, SAE4340, AISI4145H, SAE4150, SAE8620, Europe Standard: 42CrMo4, 25CrMo4, 34CrNiMo6, 39CrNiMo3, 17NiCrMo6, 18CrNiMo7-6 ...