Buy Round Belts Online in Australia
Round Belt Selection — Quick Reference
Round belts (O-ring belts) are circular-section drive belts used on light industrial conveyors, packaging, and small drives with V-pulleys (circular grooves). Their key advantage: they handle non-parallel shaft drives where flat/V-belts can't track. Selection turns on diameter, length method (continuous vs weld-to-length stock), and construction.
| Belt Type | Construction | Best For |
|---|---|---|
| Solid Polyurethane (PU) — Weldable Stock | Solid PU rod, melt-welded to length on-site | Custom-length conveyors, packaging, light industry |
| Reinforced PU (Cord Core) | PU with internal load-bearing cord | Higher load + tension capacity |
| Hollow PU | Hollow cross-section — very flexible | Very light loads — packaging, small product transport |
| Pre-Made Loop Belts | Endless, factory-welded | Fixed-length applications, OEM replacement |
Common diameters: 3mm, 5mm, 6mm, 8mm, 10mm, 12mm. Welding stock: heat both ends with welding tool to ~190°C, press together while molten, hold until cool — bond strength ≥ original belt. Pulley match: circular groove diameter slightly smaller than belt OD (≈80% engagement). Brands: Gates, Habasit, Megadyne. Companion: all belts, link belts, timing belts.
Round Belts for Australian Light Industrial and Conveyor Drives
Round belts (also called O-ring belts or round drive belts) are circular cross-section drive belts used in light industrial conveyors, packaging machinery, and small drive applications. They run on V-pulleys with circular grooves, suit non-parallel shaft drives where flat or V-belts can't track properly, and can be supplied in continuous loops or as weldable polyurethane stock for custom-length manufacture. AIMS Industrial supplies round belts across the diameters and constructions Australian light industrial users actually need.
The round belt types we stock
- Solid polyurethane (PU) round belt — the most common construction, weldable for custom lengths
- Reinforced PU round belt — with internal cord for higher load capacity
- Hollow round belt — for very light loads where flexibility is the priority
- Pre-made loops — endless construction for higher-load applications where joints can't be tolerated
- Weldable PU stock — sold by the metre for cutting and welding to length on site
Where round belts earn their place
- Conveyor drives — light-duty product handling where flat belts are over-engineering
- Packaging machinery — small drives in packaging lines, bag-making, and product feeding
- Office equipment — printers, copiers, and document handling equipment
- Vending and dispensing machinery — small drives in commercial vending equipment
- Non-parallel shaft drives — applications where the drive shafts aren't parallel; round belts handle the geometry
Sizing — diameter and length
Round belt sizing is by belt diameter (cross-section) and either length (for loops) or by quantity (for weldable stock sold by the metre). Common diameters range from 2mm through 20mm. Match diameter to the pulley groove size — undersized belts ride low in the groove and slip; oversized belts ride high and don't engage properly.
Welding round belts to length
Solid polyurethane round belts can be welded to custom length on site using a heated tool. The procedure: cut both ends square, heat the tool to the manufacturer-specified temperature, press both ends against the heated tool until softened, remove from the tool and quickly press the ends together. The weld cools and hardens within seconds. A properly-welded joint is typically 80-90% of the unwelded belt strength. Welding tools are stocked alongside the weldable belt stock.
Why round belts over V-belts
- Non-parallel shaft drives — round belts can twist around their own axis, V-belts cannot
- Quiet operation — no slap or chatter at the pulley engagement
- Custom lengths — weldable stock allows on-site custom lengths without specialist equipment
- Light loads — for drives where V-belts are over-engineered
- Compact installations — small pulley diameters that V-belts can't tolerate
Companion ranges at AIMS
Round belts sit alongside our broader drive belt range — see micro V-belts, narrow section cogged belts, Polyflex belts, and Polychain belts for the broader drive belt range.
Need help speccing round belt or sourcing weldable stock for an existing drive? contact our team — we'll match by diameter, length, and load.
People Also Ask — Round Belts
Q: What are round belts used for?
Round belts (also called O-ring belts or round drive belts) are used in light industrial conveyors, packaging machinery, office equipment, and small drives where non-parallel shaft layouts prevent flat or V-belts from tracking. Their circular cross-section allows them to run on crowned pulleys, twist through direction changes, and wrap over small radii that would crush conventional belt profiles.
Q: What is a weldable round belt and how is it joined?
Weldable round belts are supplied as polyurethane (PU) stock in continuous lengths that can be cut to any required length and heat-welded on site. Both ends are heated to approximately 190°C, pressed together while molten, and held until cool — the joint strength equals the belt strength when done correctly. This allows custom-length belts without waiting for factory-made loops.
Q: What diameters do round belts come in?
Common round belt diameters are 3, 5, 6, 8, 10, and 12 mm. Smaller diameters (3–5 mm) suit light office equipment and packaging machinery; larger diameters (8–12 mm) suit light industrial conveyor and drive applications requiring more load capacity. Diameter selection also depends on the groove size in the pulley.
Q: What is the difference between solid PU, reinforced, and hollow round belts?
Solid PU is the most common construction — flexible, weldable, and suitable for most light industrial drives. Reinforced PU includes an internal cord for higher load and tension capacity where a solid belt would stretch excessively. Hollow round belts have a hollow cross-section for maximum flexibility on very light loads and small radii. Pre-made loop belts are factory-welded endless belts for fixed-length applications where a field joint is not appropriate.
Q: How should a round belt pulley groove be sized?
The circular groove diameter should be sized to engage approximately 80% of the belt's outer diameter — the belt should seat in the groove without bottoming out and without excessive protrusion above the rim. A groove too large allows the belt to bottom out and lose drive friction; a groove too small creates excessive belt stress. Always match the groove radius to the belt's actual diameter, not just a nominal size.