SAE-AS8879, ADOPTION NOTICE: SCREW THREADS - UNJ PROFILE, INCH CONTROLLED RADIUS ROOT WITH INCREASED MINOR DIAMETER (14-MAY-2003) [SUPERSEDING MIL-S-8879C]
SAE-AS8879, ADOPTION NOTICE: SCREW THREADS - UNJ PROFILE, INCH CONTROLLED RADIUS ROOT WITH INCREASED MINOR DIAMETER (14-MAY-2003) [SUPERSEDING MIL-S-8879C]., MIL-S-8879C, dated 25 July 1991, and AMENDMENT 1, dated 2 September 1992, are
hereby canceled, and superseded by the Society of Automotive Engineers (SAE) Aerospace Specification AS8879. Threads identified as Application Category
\"Other Thread\" in MIL-S-8879C are identified as \"Category 1\" threads in AS8879. Threads identified as Application Category \"Safety Critical Thread\"
in MIL-S-8879C are identified as \"Category 2\" threads in SAE-AS8879. SAE-AS8879, \"Screw Threads - UNJ Profile, Inch Controlled Radius Root with Increased Minor Diameter\", was adopted on 14-MAY-03 for use by the Department of Defense (DoD). Copies of this document may be purchased from the Society of Automotive Engineers Inc., 400 Commonwealth Drive, Warrendale, PA 15096-0001.
That SAE Aerospace Standard (AS) specifies the characteristics of the UNJ profile inch series of screw threads, to include a mandatory controlled radius of 0.18042P to 0.15011P at the root of the external thread and with the minor diameter of both external and internal threads increased to provide a basic thread height of 0.5625H in order to accommodate the external thread maximum root radius. The following detailed requirements are included: a. UNJ basic profile and design profiles; b. standard series of diameter-pitch combinations for nomral thread diameters from .060 to 6.000 inches; c. standard thread classes and form tolerances; d. formulae for thread dimensions and tolerances; e; method of designating UNJ threads; f. inspection and verification requirements; g. tables for selected diameter-pitch combinations for aerospace screws, bolts, nuts, shaft and bearing retaining screw threads, fluid fittings, and other component thread sizes; h. tables for UNJ screw threads limiting dimensions and tolerances; and i. symbols for UNJ thread dimensions and tolerances.