BS 7161 specifies the dimensions for interchangeability of propeller bosses and propeller shaft ends in the shaft.
BS 7161 applies to shaft diameter range of 20 to 160 mm with a taper of 1: 10^1), intended for installation on inboard-engined pleasure craft.
BS 7161 on the specification for propeller shaft ends and bosses for inboard-engined pleasure craft is useful for:
Inboard engines are mounted inside the hull's midsection or in front of the transom. The engine turns a drive shaft that runs through the bottom of the hull and is attached to a propeller at the other end.
BS 7161 provides you with dimensions and gives you construction details. BS 7161 provides you with the tolerances and threads. BS 7161 provides you with the designations. BS 7161 helps you with the interchangeability of propeller bosses and propeller shaft ends in the shaft.
ISO 4566:1985