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- 40 Chain Number
- 1 Strand
- 21 Teeth
- 3.617 in Outside Diameter
- 1.1875 in Finished Bore
features
- Conforms to ANSI B29.1-1975 standards
| Bore Type | Bored to Size |
| Outside Dia. [Min] | 3.6170 in |
| Hardened Teeth | Without Hardened Teeth |
| Inch/Metric | Inch |
| Single Strand Tooth Thickness | 0.284 in |
| Keyway Size | 1/4 x 1/8 |
| Hub Projection | 0.72 in |
| Pitch Diameter | 3.355 in |
| Chain Pitch | 1/2 in |
| Length Through Bore | 1 in |
| Set Screw Size | 5/16-18 X 5/16 |
| No. of Screws | 2 |
| Material | Steel |
| Pitch Diameter [Min] | 3.355 in |
| Hub Length Thru | 0.716 in |
| No. of Strands Across | 1 |
| Outside Dia. | 3.6170 in |
| Sprocket Style | B |
| Caliper Diameter | 3.0334 in |
| Width Across Teeth | 0.284 in |
| Finished Bore | 1 3/16 in |
| Hub Dia. | 2 3/4 in |
| Martin No. | 40BS21 |
| No. of Teeth | 21 |
| Keyway | w/Keyway & Set Screw |
| Chain No. | 40 |
| Weight | 1.53 LB |
| EAN or UPC | 697950005171 |
