Taper lock bushes are the standard method of mounting pulleys, sprockets, and couplings onto shafts across industrial drives. Each bush series matches a specific taper bore machined into the hub. Selecting the correct bush ensures concentric fit, easy removal during maintenance, and correct keyway alignment. This reference covers the most commonly stocked series for UAE MRO and project supply.
How taper lock works
The bush has a tapered outer surface that mates with a matching taper bore in the pulley or sprocket hub. Cap screws pull the bush into the taper, creating a clamp fit on the shaft.
Removal uses jacking screws threaded into tapped holes in the bush — never lever against the hub or damage the taper surfaces.
Standard bush series reference
| Bush series | Typical max bore (mm) | Common hub types |
|---|---|---|
| 1008 | 14 | Small SPZ pulleys, light sprockets |
| 1108 | 16 | Compact drives |
| 1210 | 25 | SPA/SPB single-groove pulleys |
| 1610 | 42 | SPB pulleys, 08B sprockets |
| 2012 | 50 | SPB/SPC, 10B/12B sprockets |
| 2517 | 60 | Heavy SPB/SPC, 12B/16B |
| 3020 | 75 | Large industrial drives |
| 3030 | 90 | Process equipment, large sprockets |
| 3535 | 100 | Heavy-duty drives |
| 4040 | 110 | Large bore applications |
| 5050 | 125+ | Maximum standard series |
Keyway reference (typical metric)
Each bush bore includes a standard keyway. Shaft keyway must match. If shaft is keyless, confirm whether drive relies on friction grip only — not recommended for high torque.
| Shaft bore (mm) | Typical key (mm) | Bush series example |
|---|---|---|
| 20–22 | 6 × 6 | 1210 |
| 25–28 | 8 × 7 | 1210 / 1610 |
| 30–38 | 10 × 8 | 1610 / 2012 |
| 42–48 | 14 × 9 | 2012 |
| 50–55 | 16 × 10 | 2517 |
| 60–65 | 18 × 11 | 3020 |
Matching bush to hub
The pulley or sprocket marking usually includes bush series — e.g. 'SPB 200-4 TL 2517' means SPB profile, 200 mm pitch, 4 grooves, taper lock 2517 bush.
Never install a 2012 bush in a 2517 taper bore — taper angles and bolt circles differ. Mixing series damages hub and bush.
Installation and torque
- Clean taper surfaces on shaft, bush, and hub before assembly
- Hand-fit bush into hub, align cap screw holes
- Slide onto shaft to approximate position — do not force with hammer
- Tighten cap screws alternately in stages to recommended torque
- Check runout after installation on high-speed drives
Common mistakes
- Ordering bush by shaft size without confirming hub taper series
- Using wrong key size — partial key engagement fails under load
- Overtightening cap screws without staged tightening
- Prying bush off with chisel instead of jacking screws
- Reusing cracked or galled bushes after improper removal
RFQ checklist
- Bush series stamped on hub or pulley marking
- Shaft diameter (mm)
- Keyway width × height on shaft
- Hub type (pulley, sprocket, coupling)
- Quantity of bushes and cap screws if separate