Tritan sprocket 35bs12hx5/8, 3/8 pitch, 5/8 finished bore, 12 teeth tritan quality all steel sprocket for roller chain. Features black oxide finish for corrosion resistance. Includes keyway & 2 set screws. Teeth are hardened providing extra wear life, extending chain life and saving downtime and replacement cost. . Includes a recessed groove in hub for chain clearance.