Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
When your belt drive system suffers from misalignment, slack, or premature belt wear, the culprit is often a poorly engineered idler pulley. DIY builders, machine fabricators, and workshop engineers who demand consistent belt tension and smooth rotation need a guiding wheel they can rely on — one that won't introduce wobble or friction into the drivetrain.
These aluminium flat belt idler pulleys are CNC-machined from aluminium alloy and fitted with a pre-installed bearing for low-friction, free-spinning operation. Available in outer diameters from 30mm to 80mm (~1.18" to 3.15") and center hole sizes from 5mm to 20mm (~0.20" to 0.79"), with groove profiles spanning U6, U8, U10, and U12 to match a range of flat belt widths. Each variant is sold individually or in packs of 3 or 5 for multi-pulley builds.
Typical applications include flat belt idler tensioner setups on CNC router Z-axis drives, DIY conveyor belt guiding systems, 3D printer belt path routing, and light-duty power transmission rigs where a compact aluminium flat belt pulley bearing wheel is needed to redirect or tension a flat or round belt.
Turned from aluminium alloy for a lightweight yet rigid pulley body. Consistent concentricity minimises belt vibration and runout across all size variants.
Each pulley ships with a bearing already pressed in, enabling smooth, low-friction rotation on a fixed shaft — no additional bearing sourcing or pressing required.
Covers U6 through U12 groove profiles across outer diameters of 30mm, 40mm, 60mm, and 80mm, with center holes from 5mm to 20mm to suit M5–M20 shafts or bolts.
The U-shaped groove keeps flat and round belts centred on the pulley face, reducing lateral drift and extending belt service life in tensioner and idler roles.
Order a single unit for a replacement or prototype, or choose a 3-pack or 5-pack for multi-axis machines, conveyor systems, or workshop stock — with per-unit savings on larger quantities.
Standard metric hole sizing and clean machined faces make these pulleys straightforward to mount on threaded rod, shoulder bolts, or custom shafts in DIY belt drive and guiding wheel applications.
| Material | Aluminium alloy (CNC-machined) |
|---|---|
| Outer Diameter (OD) | 30mm / 40mm / 60mm / 80mm (see variant options) |
| Center Hole Diameter | 5mm / 6mm / 7mm / 8mm / 10mm / 12mm / 14mm / 15mm / 16mm / 20mm (see variant options) |
| Groove Profile | U6 / U8 / U10 / U12 (see variant options) |
| Bearing | Pre-installed (type: see variant options) |
| Belt Compatibility | Flat belt, round belt, O-ring belt |
| Finish | Natural machined aluminium |
| Pack Quantity | 1 pcs / 3 pcs / 5 pcs (see variant options) |
| Weight (per piece) | See variant options |
The U-number refers to the groove width, which should match your belt width. U6 suits narrower belts (typically ~6mm wide), U8 for ~8mm, U10 for ~10mm, and U12 for ~12mm belts. Measure your belt's width and select the matching profile to ensure the belt seats correctly in the groove without slipping sideways.
Select the hole diameter that matches your shaft or bolt diameter. For example, if you're mounting on an M8 shoulder bolt, choose the 8mm hole variant. Available sizes run from 5mm to 20mm. If your shaft is metric and falls between listed sizes, size up to the next available hole and use a sleeve or spacer for a snug fit.
The bearing comes pre-installed in the pulley. You do not need to source or press a bearing separately — the pulley is ready to mount on a shaft straight out of the pack.
The aluminium body has inherent corrosion resistance suitable for typical indoor workshop conditions. For prolonged exposure to moisture, consider applying a light coating of machine oil to the bearing and exposed metal surfaces. These pulleys are not rated for fully outdoor or submerged applications.
These are designed for light-to-medium duty belt tensioning and guiding applications such as CNC machines, 3D printers, and small conveyor systems. Exact load and RPM ratings depend on the specific bearing installed in each size variant. For heavy industrial loads or high-speed applications, contact us to confirm suitability before ordering.
Multi-axis machines, conveyor systems, and belt routing setups often require multiple idler pulleys. Ordering a 3-pack or 5-pack reduces the per-unit cost compared to buying individually, and ensures you have matched pulleys from the same production batch — useful for maintaining consistent belt tension across multiple guide points.
These pulleys feature a U-groove profile designed for flat belts, round belts, and O-ring belts. They are not designed for toothed timing belts (which require a matching tooth profile) or V-belts (which require a V-groove). Use them as idler tensioners or guide wheels in flat or round belt drive systems only.
