Finishied bore sprockets for roller chains,teech: induction hardness(hrc45-55),final bore tolerance H7; roughness value RA1.6,keyway to DIN 6885/BS4235,islocated on center line of tooth.Two grub screw holes.

06B(PITCH-9.525MM)  08B(PITCH-12.70MM)   10B(PITCH-15.875MM)   12B(PITCH-19.05MM)  16B (PITCH-25.4MM)    20B (PITCH-31.75MM)