[RC-Monster Mike]

The pinions are alloy steel, but not hardened. They work fine on plastic/delrin, but the hardened steel spur of a 1/8 buggy will eat them pretty quick. I think ideally you would want the pinion to be a harder material than the spur, as it gets 3-4 times more wear (12 pinion on a 46 spur - the pinion must turn 3.8 times to each one revolution on the spur, so it would stand to reason that it would wear out 3.8 times as fast).