by clamping together two faces perpendicular to the axis of rotation, e.g. with bolted flanges

Full Title

Couplings for rigidly connecting two coaxial shafts or other movable machine elements (attachment of wheels to axles for railway carriages B60B; for attachment of cranks to their shafts F16C3/10) > for connecting two abutting shafts or the like > by clamping together two faces perpendicular to the axis of rotation, e.g. with bolted flanges