Stem Pinions


Our stem pinions have a small number of teeth cut integrally with the steel shaft. The tooth undercut is minimized using a specially enlarged pitch diameter. When operating with a standard spur gear, the stem pinion increases the gear ratio typically found in spur gear drives.
Please note: Stem pinions do not mate with each other, with internal gears, or with 11-tooth spur gears. However, they operate satisfactorily with all other standards 14 1/2° PA spur gears.
Many different gears with various bores, keyways, and setscrews are usually stocked. Still, if the specific bore/keyway/set screw combination required is not readily available, our machining experts can replace any non-hardened gear and ship it within 24 days Hour. Just ask!

Product Features

  • Our stem pinions have fewer teeth than standard spur gears.
  • The teeth are integrally cut with the steel shaft for increased reliability.
  • Stem pinions enable higher gear ratios for improved handling compared to spur gear drives.
  • Rod pinions can easily be used with standard 14 1/2° PA spur gears.
  • Available in 20 DP to 6DP (diameter pitch)