| 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 | |
| 10 (4.89%) | 3.5 | 89 | 3.6 | 91 | 1.5 | 38 | 1.5 | 40 | ||
| 12 (3.41%) | 4.1 | 104 | 4.3 | 109 | 1.5 | 38 | 1.5 | 40 | ||
| 15 (2.19%) | 5.1 | 130 | 5.3 | 135 | 1.5 | 38 | 1-3/16, 1-1/4 | 1.5 | 30, 40 | |
| 17 (1.70%) | 5.8 | 147 | 6.1 | 155 | 1.5 | 38 | 40 | 40 | ||
| 18 (1.52%) | 6.1 | 155 | 6.3 | 160 | 1.5 | 38 | 1-1/4, 1-1/2 | 1.5, 2.5 | 40, 60 | |
| 20 (1.23%) | 6.8 | 173 | 7.0 | 178 | 1.5 | 38 | 1-1/4 | 1.5, 2.5 | 40, 60 | |
| 28 (0.63%) | 9.7 | 246 | 9.7 | 246 | 1.5 | 38 | 1.5, 2.5 | 40, 60 | ||
Round bore molded and split sprockets are frequently furnished with two keyways. Use of two keys is NOT REQUIRED nor recommended. Round bore sprockets do not have setscrews for locking the sprockets in place. As with square bore sprockets, only the center-most sprocket must be locked down. Imperial 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.
