Bend and Snub Pulleys Increasing Wrap Angle Without Moving the Drive
Bend and snub pulleys that increase belt wrap angle on the drive without relocating it. CNC machined, balanced to ISO 1940 G6.3, built to your drawing.
A bend pulley changes the belt direction, and a snub pulley does the narrower job of increasing the wrap angle on a drive pulley. Both are usually unpowered, so they transmit little or no torque - but they carry the full belt tension of the run they sit on, which is what sizes them.
The distinction matters when you order. A snub pulley sits close to the drive, often with a small wrap of its own, and its job is to buy traction. A bend pulley is placed wherever the conveyor route needs to turn, and its job is geometry.
What You Are Actually Getting
| Parameter | Specification |
|---|---|
| Function | Increase wrap angle on the drive, or change the belt direction on the route |
| Torque | Normally none - sized by belt tension, not by drive power |
| Machining | CNC lathes to ±0.01 mm on shell and shaft |
| Balancing | Dynamic balancing to ISO 1940 grade G6.3 |
| Shell | Carbon steel, or wing construction where material build-up is a problem |
| Shaft | 45# steel, equivalent to DIN C45 / JIS S45C / AISI 1045 |
| Lagging | Usually plain; lagged where the bend pulley is also a drive or where traction is needed |
| Diameter | Same standard range as the tail pulley at that belt width |
Bend and Snub Pulley Diameter Range
Bend pulleys use the tail pulley diameter range. Note the constraint: a bend pulley must not be smaller than the minimum bend diameter the belt construction allows, whatever the table says.
| Belt width (mm) | Standard diameter (mm) | Typical position |
|---|---|---|
| 500 | 250 - 500 | Snub at the drive, or route bend |
| 650 | 250 - 630 | Snub at the drive, or route bend |
| 800 | 250 - 1000 | Snub at the drive, or route bend |
| 1000 | 250 - 1600 | Bend at a transfer tower |
| 1200 | 250 - 1600 | Bend at a transfer tower |
| 1400 | 315 - 1600 | Bend, or snub on a dual-drive head |
| 1600 | 400 - 1600 | Bend, or snub on a dual-drive head |
| 1800 | 400 - 1600 | Bend on long overland routes |
| 2000 | 500 - 1600 | Bend on long overland routes |
| 2200 | 630 - 1600 | Bend on long overland routes |
| 2400 | 800 - 1600 | Bend on long overland routes |
The lower bound rises with belt width because the belt carcass, not the structure, sets the minimum bend diameter. Check it against your belt spec before ordering.
Getting Traction Without Rebuilding the Drive
Wrap angle is the cheapest traction
Adding a snub pulley to increase wrap is usually cheaper than a larger drive pulley or a second drive motor. It is the first thing to consider when a drive slips under load.
But wrap is not free
Every added wrap adds belt tension on the return side and adds a bend the carcass has to accept. A snub pulley that is too small will damage a steel cord belt while solving the slip.
Position sets the load
A snub pulley close to the drive sees nearly the full drive tension on both sides. A bend pulley further along sees the tension of its own run, which is often much lower. Same component, very different sizing.
Crown or flat
A crowned face helps centre the belt on some installations and causes problems on others. Flat face plus correct alignment is the safer default - specify crown only where the belt design calls for it.
Wing construction
Where a bend pulley sits at a transfer point and collects material, wing construction sheds it. Everywhere else, a smooth shell is quieter and cheaper.
Where Bend and Snub Pulleys Are Used
- Drive traction — A snub pulley on the return side of the drive increases wrap without changing the drive position or the gearbox.
- Route geometry — Transfers between conveyor sections, changes of incline, and the return run under a tower.
- Take-up systems — Bend pulleys are used in gravity take-up towers to route the belt through the counterweight.
Bend and Snub Pulleys FAQ
Bend pulley or snub pulley - what is the difference?
A snub pulley is a bend pulley used specifically to increase wrap angle at a drive. The components are the same; the name describes the job. If a supplier quotes both at different prices for the same drawing, ask why.
Does a bend pulley drive anything?
Normally no. It turns on the belt. That is why it is sized by tension rather than power, and why an undersized bend pulley fails at the shaft or the bearing rather than at the shell.
Will a snub pulley stop my drive slipping?
It is the cheapest thing to try first, and often enough. If the drive still slips with adequate wrap, the problem is the lagging or the belt tension, not the wrap angle.
Can the bend pulley be smaller than the tail pulley?
Only down to the minimum bend diameter your belt construction allows. For a fabric belt that is fairly small; for steel cord it can be large. Never specify below it, whatever the structure allows.
How Orders Run
T/T — 40% deposit with order, 60% balance before shipment. L/C at sight accepted for container orders.
Quoted per order. The schedule depends on the drawing, the quantity and the material — we state a firm date with the quotation instead of a catalogue figure.
15 months from B/L date against manufacturing defects. Claims supported by photos and batch number.
Packing, minimum order and Incoterms are set out in full on the quotation page.
Bend and Snub Pulleys Built to Your Drawing
Send the belt width, the duty and, if you have one, the drawing. We will specify it, quote within 24 hours, and ship samples in 2–3 days.
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