1. This British Standard specifies the materials, dimensions and inspection requirements for aluminium alloy bolts with 100°countersunk heads and Unified threads for aircraft.
BS 2A 175:1962 history
2018BS 2A 175:1962+A3:2018 Aerospace Series. Specification for bolts, 100° countersunk head, D-slot recess in anodized aluminium alloy (unified threads)
1962BS 2A 175:1962 Specification for 100 ° countersunk head aluminium alloy bolts (Unified threads) for aircraft