Stem Pinions | Boston Gear

Boston Gear's stem pinions feature small numbers of teeth that are cut integral to the steel shaft. Using a special, enlarged pitch diameter minimizes the undercutting of the teeth. When run with standard stock spur gears, stem pinions increase the ratios normally found in spur gear drives.

Please note: Stem pinions are not intended to be operated with each other, with internal gears, or with eleven-tooth spur gears. They will, however, run satisfactorily with all other standard 14 1/2° PA spur 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!

Product Features

Boston Gear's stem pinions have a smaller number of teeth than standard spur gears.
Teeth are cut integral to steel shaft for greater dependability.
Stem pinions facilitate higher gear ratios than are possible with spur gear drives for improved operation.
Boston Stem Pinions can be readily used with standard 14 1/2° PA spur gears.
Available from 20 DP to 6DP (Diametral Pitch)