Flansch

A flange is a projecting rim or collar used to join two parts or shafts by bolting their faces together.

Bolted face to face, often with a gasket, it makes a strong, sealed connection that can transmit torque or carry a pipe joint.

Flanges are used on the propeller shaft, axles, exhaust, and pipework. The correct flange matches the bolt pattern and the mating part.