BS A 274:1981

This standard BS A 274:1981 Specification for procurement of alloy steel bolts, metric, with a minimum tensile strength of 1100 MPa is classified in these ICS categories:

• 49.030.20 Bolts, screws, studs
• 77.140.20 Stainless steels

This British Standard specifies the performance and manufacturing requirements for forged bolts made of alloy steel heat treated to produce a minimum tensile strength of 1100 MPa.

This standard invokes product qualification testing requirements and quality assurance approval procedures for the manufacture of aerospace standard parts, thus making it mandatory that bolts supplied in accordance with this standard are restricted to suppliers who can demonstrate conformance to these requirements.

It is mandatory that bolts produced in accordance with this British Standard have forged heads and threads rolled after heat treatment. Cold working of the underhead fillet radius is mandatory except as specified herein (see 5.3.4).