
Hardened aluminium pinion, 64 pitch 17 teeth, included setscrew. The "Pro" Pinions are precision machined from aircraft aluminum, lightened and then they're coated twice with a super hard, black anodize. Recommended for onroad, but they can be run off road. Tooth number stamped on each pinion. 1/8 inch bore. One 5-40 set screw included.