Open Gearing


Internal Gears

Boston Gear's internal gears are spur gears turned "inside out." In other words, the teeth are cut into the inside diameter while the outside diameter is kept smooth. This design allows for the driving pinion to rotate internal to the gear, which, in turn, allows for clean operation. Intended for light duty applications, these gears are available only in brass. When choosing a mating spur gear, always remember that the difference in the number of teeth between the internal gear and pinion should not be less than 15 (14 1/2° PA) or 12 (20° PA).

    • Available in 14 1/2° and 20° PA, our internal gears are designed to accommodate a wide range of equipment.
    • Manufactured from brass, these gears are ideal - and cost-effective - for a broad range of light-duty applications.
    • Their non-binding tooth design ensures smooth, quiet operation.
    • Pitch Diameter from 1" thru 6"
    Boston Gear
    701 Carrier Dr.
    Charlotte, NC 28216
    Web: CONTACT
We are now a part of Regal Rexnord.