Product Description
The Tsubaki 40B21F is a single-strand, Type B finished bore roller chain sprocket designed for ANSI #40 (1/2" pitch) roller chain. It features a hub extension on one side (Type B) with a factory-machined keyway and two set screws, making it ready for direct shaft mounting. The stock bore is 5/8 in and can be re-bored up to a maximum of 1-7/8 in to suit your shaft size. Constructed of carbon steel with hardened teeth, this sprocket is engineered for industrial power transmission, conveyor, and drive applications requiring reliable performance.
Technical Specifications
| Specification | Value |
|---|---|
| Brand | Tsubaki (U.S. Tsubaki) |
| Model / Part Number | 40B21F |
| Chain Number (ANSI) | #40 |
| Chain Pitch | 1/2 in (0.500 in) |
| Number of Teeth | 21 |
| Hub Type | Type B (hub extension one side) |
| Bore Type | Finished Bore (with keyway & 2 set screws) |
| Stock Bore Diameter | 5/8 in (0.625 in) |
| Maximum Bore Diameter | 1-7/8 in (1.875 in) |
| Outside Diameter (OD) | 3.620 in |
| Pitch Diameter | 3.355 in |
| Caliper Diameter | 3.033 in |
| Hub Diameter | 2.750 in (2-3/4 in) |
| Length Through Bore (LTB) | 1.000 in |
| Tooth Nominal Width | 0.284 in |
| Chain Roller Diameter | 0.312 in |
| Chain Inside Width | 5/16 in |
| Number of Strands | Single |
| Shaft Orientation | Horizontal |
| Material | Carbon Steel |
| Hardened Teeth | Yes |
| Keyway | Yes (standard keyway included) |
| Set Screws | 2 (directly over keyway & 90° from keyway) |
| Bushing Required | None |
| Standards | ANSI |
| Weight | ~1.730 lb |
We warranty all items for 30 days from date of purchase.
Other Details
We warranty all items for 30 days from date of purchase. If you experience any issues with your item within this period, please contact us and we will work with you to resolve the problem. This warranty covers defects in functionality but does not cover damage caused by misuse, improper installation, or normal wear and tear.Product Videos
Custom Field
GTIN 679523686161
Hole Diameter 2.750 in
Material Carbon Steel
Diameter 2.750 in
Manufacturer Tsubaki
Part Number 40B21F
Shelf GS 38
Bore Diameter 0.625 in (stock)
Model 40B21F
MPN 40B21F
Type Roller Chain Sprocket
