Tham khảo tài liệu 'materials science and engineering handbook [crc press 2001] episode 7', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Table 193. Hardness of Malleable Iron Castings Specification Number Grade or Class Hardness hb Ferritic ASTM A47 A338 ANSI FED QQ-I-666c 32510 156 max 35018 156 max ASTM A197 156 max Pearlitic and Martensitic ASTM A220 ANSI MIL-I-11444B 40010 149-197 45008 156-197 45006 156-207 50005 179-229 60004 197-241 70003 217-269 80002 241-285 90001 269-321 Automotive ASTM A602 SAE J158 M3210 156 max M4504 a 163-217 M5003 a 187-241 M5503 b 187-241 M7002 b 229-269 M8501 b 269-302 a Air quenched and tempered b Liquid quenched and tempered Source data from ASM Metals Reference Book Second Edition American Society for Metals Metals Park Ohio 44073 p171 1984 . 2001 CRC Press LLC Table 194. Hardness of Ductile Irons Specification Number Grade or Class Hardness Hb ASTM A395-76 ASME SA395 60-40-18 143-187 ASTM A476-70 d SAE AMS5316 80-60-03 201 min ASTM A536-72 MIL-1-11466B MR 60-40-18 65-45-12 80-55-06 100-70-03 120-90-02 SAE J434c D4018 D4512 D5506 D7003 170 max 156-217 187-255 241-302 MlL-I-24137 Ships Class A Class B Class C 190 max 190 max 175 max Source data from ASM Metals Reference Book Second Edition American Society for Metals Metals Park Ohio 44073 p169 1984 . 2001 CRC Press .