Boston Gear change gears are used primarily on machine tools to provide different cutting speeds while using a constant speed input. All Boston Gear change gears are manufactured with a double key to accept the compound steel bushings that connect two gears together, allowing them to spin on an intermediate shaft. The change gears we stock range from 20-tooth through 128-tooth gears, in one tooth increments, depending upon the diametral pitch, for a nearly infinite number of ratio possibilities. Be sure to ask for the Boston Gear compound steel bushings designed specifically for use with these gears.

Many different gears with a variety of bore sizes, keyways, and setscrews are routinely in stock, but if the particular bore/keyway/setscrew combination needed is not readily available, our machining experts can alter any non-hardened gear and ship it within 24 hours. Just ask!