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E-25 General Standards for Aerospace and Propulsion Systems
AS8879D - Screw Threads - Unj Profile, Inch Controlled Radius Root With Increased Minor Diameter
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Screw Threads - Unj Profile, Inch Controlled Radius Root With Increased Minor Diameter
This SAE Aerospace Standard (AS) specifies the characteristics of screw threads - UNJ profile inch series, including a mandatory controlled radius as specified in Table 1 at the root of the external thread. The minor diameter of both external and internal threads provides a basic thread height of .5625H to accommodate the external thread maximum root radius. The following detailed design requirements are included: a. Screw threads - UNJ basic profile and design profiles. b. Standard series of diameter-pitch combinations for nominal thread diameters from 0.060 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. Tables for selected diameter-pitch combinations for close tolerance mechanical thread applications. g. Tables for screw thread - UNJ profile thread limit dimensions.
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