Conveyor coupling shafts are used to join individual lengths of conveyor screws and allow for rotation within the hanger bearing. Steel couplings are normally furnished, however couplings with hardened bearing surfaces may be furnished where highly abrasive materials are being conveyed. Jig drilling allows for ease of installation. Martin Conveyor Coupling Shaft, Hardened, 3 in Shaft Dia, 13 in Shaft Length, 2 Bolts, Steel, Protective Coating, 13 in OAL