Roller Chain Sprocket; 1" Bore; 40 Chain; 27 Teeth; 1 Row of Teeth; No Hardened Teeth; 4-37/64" Outside Diameter; 4.307" Pitch Diameter; B-Hub One Side; Finished Bore Mount; No Bushing; 1/2" Chain Pitch; ANSI Roller Chain; Keyway; Steel Material