Historical
BS 4395-2:1969
Specification for high strength friction grip bolts and associated nuts and washers for structural engineering. Higher grade bolts and nuts and general grade washers (British Standard)
Higher grade friction grip bolts (10.9) and nuts (12) and general grade washers. Dimensions in the nominal size range 16 mm to 33 mm inclusive and mechanical properties are specified with details of tests, inspection procedure and marking.
British Standards Institution [bsi]