AS8879A: Screw Threads - UNJ Profile, Inch

Features

Issuing Committee: E-25 General Standards for Aerospace and Propulsion Systems

Scope

Content

This SAE Aerospace Standard (AS) specifies the characteristics of the UNJ profile inch series of screw threads, to include a mandatory controlled radius of 0.18142P to 0.15011P at the root of the external thread and with a 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 nominal 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
Acceptance 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.
i
Symbols for UNJ thread dimensions and tolerances.

Meta Tags

Topics: Pitch
Production control
Manufacturing processes
Safety critical systems
Screws

Details

DOI: https://doi.org/10.4271/AS8879A

Pages: 33

Citation: SAE International Technical Standard, Screw Threads - UNJ Profile, Inch, SAE Standard AS8879A, Revised January 1999, Issued October 1996, https://doi.org/10.4271/AS8879A.

Additional Details