To fully define the following requirements for bolts with spline and hexagon heads of strength class up to but not including 1250 MPa:

a. Head dimensions (see 3.1)

b. Shank dimensions (see 3.2)

c. Geometric control (see 3.3)

d. Surface texture (see 3.4)

This document is based on one class of thread after all processing, including coating or plating, has been completed as follows: tolerance class 4h6h.

For particulars of thread, see AS1370. For thread runout and lead threads, see AS3062.

To fully define the following requirements for nuts with spline, plain hexagon and castellated configurations of strength class up to and including 1100 MPa:

a. Nut dimensions (see 4.1)

b. Geometric control (see 4.2)

c. Surface texture (see 4.3)

For particulars of threads, see AS1370.

This document is based on the following classes of internal threads after all processing, including coating or plating, has been completed:

Tolerance class 4H6H for sizes up to and including 5 mm

Tolerance class 4H5H for size 6 mm and larger

For particulars of thread, see AS1370.

Purpose:

To establish design requirements for metric aerospace bolts, screws and nuts primarily for use on propulsion systems.

The smaller thread sizes are usually referred to as screws. For the purpose of this document, the term bolt will be used for all sizes.