This SAE Recommended Practice covers methods for measuring@ classifying@ and specifying decarburization in the threaded section of hardened and tempered steel bolts@ screws@ studs@ and similar parts. It is not intended to cover products which are specifically carburized to achieve special properties.
SAE J121M-2013 history
2013SAE J121M-2013 Decarburization in Hardened and Tempered Metric Threaded Fasteners
2013SAE J121-2013 Decarburization in Hardened and Tempered Unified Threaded Fasteners
1997SAE J121M-1997 Decarburization in Hardened and Tempered Metric Threaded Fasteners
1997SAE J121-1997 Decarburization in Hardened and Tempered Unified Threaded Fasteners
1996SAE J121M-1996 Decarburization in Hardened and Tempered Metric Threaded Fasteners@ Recommended Practice (08-1996)
1996SAE J121-1996 Decarburization in Hardened and Tempered Unified Threaded Fasteners@ Recommended Practice (08 1996)
1994SAE J121M-1994 DECARBURIZATION IN HARDENED AND TEMPERED THREADED FASTENERS
1994SAE J121-1994 DECARBURIZATION IN HARDENED AND TEMPERED THREADED FASTENERS
1983SAE J121-1983 DECARBURIZATION IN HARDENED AND TEMPERED THREADED FASTENERS
1976SAE J121A-1976 DECARBURIZATION IN HARDENED AND TEMPERED THREADED FASTENERS