Shaft couplings are used to connect two shafts in line and transmit power from one to the other. Rigid couplings provide a fixed union between the shafts where misalignment is not present. Special couplings can be adapted to connect shafts of different diameters. Standard material is high-strength gray iron suitable to transmit the rated load capacities of C1018 commercial shafting. Couplings are finished machined to insure proper balance. Keys are furnished for all couplings. Bearings should be positioned as close as possible to the couplings.