Overview and comparison
What are Taper Bush timing pulleys?
Taper Bush timing pulleys (TB timing pulleys) are synchronous pulleys to ISO 5294 standard, mounted on the shaft via a Taper Bush conical locking element. Unlike pilot bore pulleys, the hub is machined with a built-in conical seat — Taper Bush clamping, bolt tightening, fast assembly and disassembly without heating or press tools.
Taper Bush mounting is preferred for heavier drives, higher torque and frequent disassembly — e.g. seasonal maintenance, belt replacement or machine reconfiguration. Nibora Ltd. supplies series L (pitch 9.525 mm) and H (pitch 12.7 mm) in steel (standard) and grey cast iron (higher tooth counts).
Pilot bore vs. Taper Bush — comparison
| Criterion | Pilot bore (ISO 5294) | Taper Bush (ISO 5294 TB) |
|---|---|---|
| Mounting | Bore machined to shaft diameter | Conical locking element (TB) |
| Dismounting | Press tools required | Fast — bolts only |
| Concentricity | High (after boring) | Very high (taper self-centering) |
| Torque capacity | Medium | Higher for same hub diameter |
| Application | Light/medium drives | Medium/heavy drives |
| Disassembly frequency | Infrequent | Suitable for frequent dismounting |
Advantages of Taper Bush mounting
- Self-centering taper — high concentricity without boring
- Mount and dismount with bolts only, no heating or press
- Higher torque capacity for the same hub diameter
- Fast belt replacement during seasonal maintenance or breakdown
- Suited to medium and heavy drives with frequent disassembly
Series and catalogue data
Series and technical data
The series cover pitch 9.525 mm (L) and 12.7 mm (H), from 16 to 120 teeth, in steel and cast iron:
| Series | Pitch | Belt width (F) | Teeth | Taper Bush | Material |
|---|---|---|---|---|---|
| L 050 | 9.525 mm (3/8″) | 19.0 mm (1/2″) | 18–120 | 1108–2012 | Steel / Cast iron |
| L 075 | 9.525 mm (3/8″) | 25.0 mm (3/4″) | 18–120 | 1108–2012 | Steel / Cast iron |
| L 100 | 9.525 mm (3/8″) | 31.0–32.0 mm (1″) | 18–120 | 1108–2012 | Steel / Cast iron |
| H 100 | 12.7 mm (1/2″) | 31.0–34.0 mm (1″) | 16–120 | 1108–2517 | Steel / Cast iron |
| H 150 | 12.7 mm (1/2″) | 45.0–46.0 mm (1½″) | 18–120 | 1210–2517 | Steel / Cast iron |
| H 200 | 12.7 mm (1/2″) | 58.0–60.0 mm (2″) | 18–120 | 1210–2517 | Steel / Cast iron |
Catalogue data — series L 050
Pitch 9.525 mm · Belt width F = 19.0 mm · Steel: 18–40 teeth · Cast iron: 72–120 teeth
| Code | Type | Mat. | Teeth | Taper Bush | Bore max | dp (mm) | de (mm) | Df (mm) | Dm (mm) | Di (mm) | F (mm) | L (mm) | R | Flange № | Kg |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| TL 18 L 050 | 10F | St | 18 | 1108 | 28 | 54.57 | 53.81 | 60 | 45 | — | 19.0 | 22.0 | 3 | 308 | 0.20 |
| TL 20 L 050 | 10F | St | 20 | 1108 | 28 | 60.64 | 59.88 | 66 | 48 | — | 19.0 | 22.0 | 3 | 310 | 0.27 |
| TL 24 L 050 | 10F | St | 24 | 1108 | 28 | 72.77 | 72.00 | 79 | 54 | — | 19.0 | 22.0 | 3 | 313 | 0.45 |
| TL 28 L 050 | 10F | St | 28 | 1108 | 28 | 84.89 | 84.13 | 91 | 65 | — | 19.0 | 22.0 | 3 | 316 | 0.65 |
| TL 30 L 050 | 10F | St | 30 | 1108 | 28 | 90.96 | 90.20 | 97 | 70 | — | 19.0 | 22.0 | 3 | 318 | 0.80 |
| TL 36 L 050 | 10F | St | 36 | 1108 | 28 | 109.15 | 108.39 | 115 | 85 | — | 19.0 | 22.0 | 3 | 323 | 1.20 |
| TL 40 L 050 | 10F | St | 40 | 1610 | 42 | 121.28 | 120.51 | 127 | 97 | — | 19.0 | 25.0 | 6 | 327 | 1.40 |
| TL 48 L 050 | 11F | St | 48 | 1610 | 42 | 145.53 | 144.77 | 152 | 88 | 120 | 19.0 | 25.0 | 6 | 334 | 2.30 |
| TL 60 L 050 | 13 | St | 60 | 1610 | 42 | 181.91 | 181.15 | — | 92 | 166 | 19.0 | 25.0 | 3 | — | 2.20 |
| TL 72 L 050 | 14 | GG | 72 | 1610 | 42 | 218.30 | 217.53 | — | 92 | 202 | 19.0 | 25.0 | 3 | — | 2.10 |
| TL 96 L 050 | 14 | GG | 96 | 2012 | 50 | 291.06 | 290.30 | — | 106 | 270 | 19.0 | 32.0 | 6.5 | — | 3.36 |
| TL 120 L 050 | 14 | GG | 120 | 2012 | 50 | 363.83 | 363.07 | — | 106 | 343 | 19.0 | 32.0 | 6.5 | — | 4.44 |
Catalogue data — series H 100
Pitch 12.7 mm · Belt width F = 31.0–34.0 mm · Steel: 16–48 teeth · Cast iron: 60–120 teeth
| Code | Type | Mat. | Teeth | Taper Bush | Bore max | dp (mm) | de (mm) | Df (mm) | Dm (mm) | Di (mm) | F (mm) | L (mm) | R | Flange № | Kg |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| TL 16 H 100 | 16F | St | 16 | 1108 | 28 | 64.68 | 63.31 | 71 | — | 45 | 31.0 | 22.0 | 9.0 | 311 | 0.42 |
| TL 18 H 100 | 16F | St | 18 | 1210 | 32 | 72.77 | 71.39 | 79 | — | 52 | 31.0 | 25.0 | 6.0 | 313 | 0.49 |
| TL 20 H 100 | 16F | St | 20 | 1210 | 32 | 80.85 | 79.48 | 87 | — | 60 | 31.0 | 25.0 | 6.0 | 315 | 0.73 |
| TL 24 H 100 | 16F | St | 24 | 1610 | 42 | 97.02 | 95.65 | 103 | — | 73.5 | 32.0 | 25.0 | 7.0 | 320 | 1.05 |
| TL 28 H 100 | 16F | St | 28 | 1610 | 42 | 113.19 | 111.82 | 119 | — | 90.5 | 32.0 | 25.0 | 7.0 | 325 | 1.50 |
| TL 30 H 100 | 16F | St | 30 | 1610 | 42 | 121.28 | 119.90 | 127 | — | 98 | 32.0 | 25.0 | 7.0 | 327 | 1.78 |
| TL 36 H 100 | 17F | St | 36 | 1610 | 42 | 145.53 | 144.16 | 152 | 92 | 121 | 32.0 | 25.0 | 7.0 | 334 | 2.80 |
| TL 40 H 100 | 17F | St | 40 | 1610 | 42 | 161.70 | 160.33 | 168 | 92 | 138 | 32.0 | 25.0 | 7.0 | 338 | 3.65 |
| TL 48 H 100 | 21F | St | 48 | 2012 | 50 | 194.04 | 192.67 | 200 | 106 | 169 | 32.0 | 32.0 | — | 342 | 4.20 |
| TL 60 H 100 | 20 | GG | 60 | 2012 | 50 | 242.55 | 241.18 | — | 106 | 223 | 34.0 | 32.0 | 1.0 | — | 3.76 |
| TL 96 H 100 | 14 | GG | 96 | 2517 | 60 | 388.08 | 386.71 | — | 119 | 366 | 34.0 | 45.0 | 5.5 | — | 7.95 |
| TL 120 H 100 | 14 | GG | 120 | 2517 | 60 | 485.10 | 483.73 | — | 119 | 462 | 34.0 | 45.0 | 5.5 | — | 10.05 |
Catalogue data — series H 200
Pitch 12.7 mm · Belt width F = 58.0–60.0 mm (2″) · Wider belt for higher power transmission
| Code | Type | Mat. | Teeth | Taper Bush | Bore max | dp (mm) | de (mm) | Df (mm) | Dm (mm) | Di (mm) | F (mm) | L (mm) | R | Flange № | Kg |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| TL 18 H 200 | 16F | St | 18 | 1210 | 32 | 72.77 | 71.39 | 79 | — | 52 | 58.0 | 25.0 | 33.0 | 313 | 0.84 |
| TL 24 H 200 | 16F | St | 24 | 1610 | 42 | 97.02 | 95.65 | 103 | — | 73.5 | 58.0 | 25.0 | 33.0 | 320 | 1.55 |
| TL 30 H 200 | 16F | St | 30 | 1610 | 42 | 121.28 | 119.90 | 127 | — | 98 | 58.0 | 25.0 | 33.0 | 327 | 2.60 |
| TL 36 H 200 | 17F | St | 36 | 2012 | 50 | 145.53 | 144.16 | 152 | 102 | 121 | 58.0 | 32.0 | 26.0 | 334 | 3.62 |
| TL 48 H 200 | 17F | St | 48 | 2517 | 60 | 194.04 | 192.67 | 200 | 119 | 169 | 58.0 | 45.0 | 13.0 | 342 | 6.47 |
| TL 60 H 200 | 20 | GG | 60 | 2517 | 60 | 242.55 | 241.18 | — | 119 | 223 | 60.0 | 45.0 | 7.5 | — | 5.86 |
| TL 96 H 200 | 20 | GG | 96 | 2517 | 60 | 388.08 | 386.71 | — | 119 | 366 | 60.0 | 45.0 | 7.5 | — | 10.83 |
| TL 120 H 200 | 20 | GG | 120 | 2517 | 60 | 485.10 | 483.73 | — | 119 | 462 | 60.0 | 45.0 | 7.5 | — | 14.95 |
Notes: Dm = hub diameter; Di = inner diameter (spoked types); F = pulley width; L = Taper Bush bore depth; R = flange-to-tooth distance; Flange № = flange code.
Taper Bush sizes and maximum bore
| Taper Bush | Max bore (mm) | Typical for teeth |
|---|---|---|
| 1108 | 28 | L 18–35, H 16–22 |
| 1210 | 32 | L 30–32, H 18–22 |
| 1610 | 42 | L 36–48, H 23–48 |
| 2012 | 50 | L 60–96, H 44–84 |
| 2517 | 60 | H 48–120 |
Timing pulleys ISO 5294
Download PDF ↓Frequently Asked Questions
What is the difference between a pilot bore and a Taper Bush timing pulley?
A pilot bore pulley is bored to the specific shaft diameter — mounting is permanent and requires press tools for removal. A Taper Bush pulley has a built-in conical seat and is mounted/dismounted with bolts only — self-centering, higher torque capacity, suitable for frequent disassembly.
When should I choose a Taper Bush pulley instead of a pilot bore?
Choose Taper Bush when: the drive is medium or heavy duty (higher torque); frequent disassembly is required (maintenance, belt replacement, reconfiguration); higher concentricity is needed; the shaft diameter is larger. Pilot bore is suitable for smaller drives and infrequent removal.
What does Di (inner diameter) mean in the table?
Di is the inner diameter of the disc body on spoked/open-centre pulley types (13, 14, 21) — those with larger tooth counts where the Taper Bush is mounted inside the disc rather than in a central hub. Di does not apply to standard flange types (10F, 11F, 15F, 16F, 17F).
How do I order a Taper Bush timing pulley?
Specify: series (L 050/075/100 or H 100/150/200), tooth count, Taper Bush size, shaft diameter. Example: TL 30 H 100, TB 1610, shaft Ø 38 mm. Contact: nibora@nibora.com, +359 64 681 058.
Can these TB pulleys be used with HTD or T profile belts?
No — the TB pulleys in this catalogue are for Imperial profiles L (9.525 mm pitch) and H (12.7 mm pitch) only. For HTD, T and BAT profiles — contact Nibora Ltd., as these series are available on special order.