| Number of Teeth (Chordal Action) | Nom. Pitch Diameter | Nom. Outer Diameter | Nom. Hub Width | Available Bore Sizes | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| in | mm | in | mm | in | mm | Round in1 | Square in | Round mm1 | Square mm | |
| 12 (3.41%) | 3.9 | 99 | 4 | 102 | 1.0 | 25 | 1, 1-1/4 | 1.5 | ||
| 16 (1.92%) | 5.1 | 130 | 5.2 | 132 | 1.0 | 25 | 1.25 | 40 | ||
| 20 (1.23%) | 6.4 | 163 | 6.4 | 163 | 1.0 | 25 | 1.5 | |||
| ||||||||||
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.
