MIL-HDBK-131A (NOTICE 1), MILITARY HANDBOOK: IDENTIFICATION MARKINGS FOR FASTENERS (HANDBOOK H-131) (27-SEP-2001)
MIL-HDBK-131A (NOTICE 1), MILITARY HANDBOOK: IDENTIFICATION MARKINGS FOR FASTENERS (HANDBOOK H-131) (27-SEP-2001)., MIL-HDBK-131A, dated 15 September 1966, has been reviewed and
determined to be valid for use in acquisition.