Roller Chain Sprocket; 3-1/4" Bore; 120-2 Chain; 12 Teeth; 2 Rows of Teeth; No Hardened Teeth; 6.498" Outside Diameter; 5.796" Pitch Diameter; B-Hub One Side; Finished Bore Mount; 1-1/2" Chain Pitch; ANSI Roller Chain Type; Keyway; Steel Material