Bolts, Screws and Nuts - External Wrenching UNJ Thread, Inch Series - Design Standard
|Publication Date:||1 November 1998|
The scope of this document is to define the following dimensional requirements for hexagon and double hexagon head bolts and nuts having a minimum tensile strength ranging up to 220 ksi.
a. Head dimensions (see 3.1)
b. Shank dimensions (see 3.2)
c. Geometric control (see 3.3)
d. Surface texture (see 3.4)
e. Dimensions for nuts (see Section 4)
For design calculations the MIL-S-8879 coarse threads, UNJC, shall be used for 0.164 size and smaller and fine threads, UNJF, for larger sizes.
For particulars of thread runout and lead threads for bolts, see AS3062.
To establish design requirements for bolts, screws and nuts in the UNJ thread inch series primarily for use in propulsion systems.
As defined by the Federal Cataloging System, thread sizes less than 0.190 are referred to as screws and larger are referred to as bolts. For the purpose of this document, the term bolt will be used for all sizes.
1.2.1 Dimensional Units: Dimensions and tolerances in this document are in inches, unless otherwise specified.
1.2.2 Coatings: Dimensions specified in this document apply after finish when bolts or nuts are plated and before finish when bolts or nuts are dry film lubricated.