Number of Teeth (Chordal Action)Nom. Pitch DiameterNom. Outer Diameter Nom. Hub Width Available Bore Sizes
inmminmminmmRound in1Square inRound mm1Square mm
12 (3.41%)3.99941021.0251, 1-1/41.52
16 (1.92%)5.11305.21321.0251.25 40
20 (1.23%)6.41636.41631.025 1.5
  1. U.S. key sizes on round bore sprockets are based on ANSI standard B17.1-1967 (R1989) and metric key sizes are based on DIN standard 6885.

  2. Do not use this sprocket with hold down guides.