These narrow pinions are manufactured by XRAY on a specially-modified precision gear machine which has ultra-precise tolerances and assures unparalleled concentricity. After machining, the edges of pinions are chamfered and then the pinions are run in. The pinions are then specially treated to give them an even hardcoating so they stay absolutely true for a long time. The pinions run great with any spur gears, and work perfectly with XRAY spur gears where even throttle on/off noise nearly disappears. You can be confident in using the new narrow pinion right from the package, knowing that you are using a pinion of leading-edge design and production. These new 40T, 42T, 44T, 46T, 48T and 50T 64-pitch narrow high-performance pinion gears are manufactured from special lightweight aircraft duraluminum are 1.5mm thinner and 25% lighter than the regular-size pinion gears.