SAE J121
SAE J121 1997-APR-01 Decarburzaton n Hardened and Tempered Unfed Threaded Fasteners
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.
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