Pulleys

Industrial Pulleys & Sheaves — V-Belt, Timing, Idler & Taper Lock

A pulley (also called a sheave) is the grooved wheel that drives or is driven by a belt — the core component of every belt-driven power transmission system from a workshop pedestal drill to a major industrial fan, conveyor or pump drive. AIMS Industrial stocks a comprehensive pulley range covering V-belt sheaves, synchronous timing pulleys, idler pulleys and matching taper lock bushes from the brands specified across Australian manufacturing, agriculture, mining and general industry.

Pulley Types — At a Glance

• V-belt pulleys (sheaves) — single, dual and multi-groove V-section pulleys in A, B, C, SPA, SPB, SPC and SPZ/Z profiles. Available in pilot bore, bored-and-keyed and taper lock configurations.
• Timing pulleys — precision synchronous pulleys for positive (non-slip) drives. HTD (3M, 5M, 8M, 14M), T5, T10, XL, L and H series.
• Idler pulleys — flat and V-groove tensioning pulleys for belt drive tension and routing. Single-row and double-row bearing configurations.
• Specialty & brand pulleys — Gates PolyChain GT sprockets for high-torque applications, Aetna pulleys for general industrial duty.

For type selection, sizing and the differences between sheave profiles, see the Pulley Types Guide.

V-Belt Pulleys

V-belt pulleys are the most common industrial drive pulley, available across the major belt sections used in Australia:

• Classical sections (A, B, C, D, E): the original V-belt profiles, still widely used in older equipment and general industrial applications.
• Narrow / wedge sections (SPA, SPB, SPC, SPZ): higher power density in a smaller envelope — the modern default for new drive designs.
• Multi-rib (Poly-V) and PolyChain GT sprockets for high-torque or high-speed applications.

Pulleys are available in pilot bore (drilled to size on installation), bored and keyed (delivered ready to fit a specific shaft), and taper lock (industry-standard system using a separate taper lock bush for shaft mounting). Taper lock is the preferred configuration for most industrial applications — fast installation, accurate centralisation, no specialised tooling required for removal.

For belt sizing, profile identification and how to measure an existing belt for replacement, see V-Belt Sizing & Identification and V-Belt: How to Measure Like a Pro.

Timing Pulleys

Synchronous timing pulleys engage the teeth on a timing belt for positive, slip-free power transmission — used wherever accurate timing matters (CNC machines, packaging equipment, indexing tables, automotive engine drives). AIMS stocks the major profiles:

• HTD curvilinear: 3M, 5M, 8M and 14M pitches. The modern standard for industrial synchronous drives.
• Imperial trapezoidal: XL (0.200" pitch), L (0.375"), H (0.500") for legacy and OEM applications.
• Metric trapezoidal: T5 (5mm), T10 (10mm) for European-spec equipment.

For timing belt selection alongside the matching pulley, see the Synchronous Timing Belt Guide. For deciding between belt and chain drive in a new installation, see Choosing Between Belt and Chain Drives.

Idler Pulleys

Idler pulleys take up belt slack, change belt direction, increase wrap angle on a small drive sheave, or maintain consistent tension on a vibrating drive. Flat idlers for the back of the belt; V-groove idlers for the belt face. Single and double-row bearing configurations to suit drive tension and speed.

Calculating Pulley Ratios & Speed

Driven pulley speed = drive speed × (drive diameter ÷ driven diameter). A 100mm drive pulley spinning at 1,800 RPM connected to a 200mm driven pulley turns at 900 RPM. For the full formula with worked examples — and the rule of thumb for changing pulley sizes to gain speed or torque — see the Pulley Speed Ratio Calculator & Formula guide. For variable-speed and CVT-style multi-speed belt drives, see the Variable Speed Belt Guide.

How to Choose the Right Pulley

• Belt section: the pulley groove must match the V-belt profile (A, B, SPA, SPB etc.) or timing belt pitch and tooth count. Mismatched profiles cause premature belt failure.
• Drive ratio: the ratio of drive to driven pulley diameter sets the output speed and torque multiplication.
• Bore method: pilot bore (for in-house machining), bored and keyed (ready-to-fit) or taper lock (interchangeable bush system).
• Material: cast iron for heavy industrial duty; aluminium for lighter applications, lower inertia and higher speeds.
• Number of grooves: single or multi-groove for higher power transmission with the same belt section.

Brand Pulleys

• Gates — 431 lines. Industry-leading belts, pulleys and PolyChain GT systems.
• Aetna — 36 lines. Pulley and sheave specialist.
• Finer Power Transmissions — 225 lines. Broad PT component range including pulleys.

Related Power Transmission Components

• Belts — V-belts, timing belts and the full belt range.
• Industrial V-Belts and Industrial Timing Belts.
• Taper Lock Bushes for shaft mounting.
• Bearings and Bearing Housings for shaft support.
• Roller Chain — alternative drive type, especially for high-shock or wet/dirty environments.
• Shaft Coupling Guide and Flexible Coupling Guide for shaft-to-shaft connections within a drive system.
• FRAS belt FAQ — fire-resistant anti-static belts for mining and explosive-atmosphere applications.

Order Pulleys from AIMS Industrial

AIMS Industrial stocks pulleys from leading brands across all major belt sections and profiles. For pulley specification help, drive design calculations, or sourcing an unusual size, contact our technical team — we ship Australia-wide from our Sydney warehouse.

People Also Ask — Industrial Pulleys

Q: What's the difference between V-belt pulleys and timing pulleys?

V-belt pulleys (also called sheaves) have angled grooves that grip a V-shaped belt by friction — used for variable-speed and slip-tolerant drives. Timing pulleys have teeth that engage a toothed timing belt for positive synchronous drive — used where shaft positions must stay coordinated. They're not interchangeable: V-belt on timing pulley loses traction; timing belt on V-pulley jumps teeth and damages both.

Q: How do I size pulleys for a new belt drive?

Start from the speed ratio (driver RPM divided by driven RPM) — that fixes the pulley diameter ratio. Then pick the smaller pulley to meet the belt section's minimum diameter (each V-belt section has a minimum recommended sheave diameter). Centre distance and belt length follow from standard belt lengths. Both Gates and Optibelt publish drive design software that handles the calculation.

Q: What's a taper lock bush and when do I use one?

A taper lock bush is a split tapered sleeve that wedges between the shaft and the pulley bore — tightening the cap screws compresses the bush radially onto the shaft, securing the pulley without keyways or set screws. They install and remove quickly with hand tools and provide a positive grip rated for high torque. The standard mounting for most industrial pulleys above 30mm bore.

Q: How tight should a V-belt be tensioned?

Belt manufacturers publish tension specs based on belt deflection at a given force — too tight loads the bearings and overworks the belt, too loose lets the belt slip and overheat. The general rule: deflect the belt span 1.5% of the centre distance with light hand pressure. For precise work use a belt-tension gauge. Re-check after 24-48 hours of operation — new belts settle and need re-tensioning.

Q: Can I mix steel and cast iron pulleys in one drive?

Mechanically yes, both materials accept the same belts. Differences: cast iron damps vibration better and is the standard for industrial drives, steel is lighter and used where mass matters or for stamped sheaves at lower cost. For high-speed applications, balanced pulleys are essential regardless of material. Don't mix manufacturers without confirming the groove profile dimensions match — small differences cause uneven belt wear.

Q: What is the minimum pulley diameter for each V-belt section?

V-belt manufacturers publish minimum pulley diameters below which belt fatigue life drops sharply. Approximate minimums for common sections: SPZ (narrow metric 10mm width) minimum 63mm diameter; SPA (13mm) minimum 100mm; SPB (17mm) minimum 140mm; SPC (22mm) minimum 224mm. Classical sections: A (13mm) minimum 76mm; B (17mm) minimum 127mm; C (22mm) minimum 178mm; D (32mm) minimum 305mm. Wedge and cogged variants tolerate slightly smaller minimums due to increased flexibility. Running a belt on an undersized pulley causes premature fatigue at the tension member — the belt cracks internally even when the outer surface looks fine. Match pulley diameter to at least the manufacturer minimum for the drive belt.

Q: How do I identify a timing pulley profile?

Timing belt pulleys are identified by three dimensions: tooth pitch (the distance from one tooth centre to the next along the belt length), tooth form (imperial trapezoidal L, H, XH; metric trapezoidal T5, T10; metric curvilinear HTD 5M, 8M, 14M; high-torque GT2, GT3), and number of teeth (which sets the pitch diameter). To identify an unknown pulley: measure the pitch by counting teeth around the circumference and measuring the pitch diameter, then check the tooth height and profile against the standard forms. HTD, GT, and old trapezoidal L-series each have visibly distinct tooth shapes. Once identified, match the pulley pitch and tooth count to the required speed ratio. Timing pulleys are not interchangeable between profiles — HTD 8M won't run on a GT 8MR pulley.

Q: Do V-belt pulleys need to be balanced?

For low-speed drives (below 1500 RPM) or small pulleys (under 200mm diameter), standard cast pulleys run without balancing issues. For high-speed drives (above 1800 RPM), large-diameter pulleys, or long shaft applications, dynamic balancing is essential to avoid vibration, bearing wear, and premature belt failure. Manufacturer catalogue pulleys are typically supplied balanced to a class appropriate to their maximum recommended RPM; custom-machined or repurposed pulleys should be dynamically balanced before commissioning. Persistent drive vibration despite correct alignment and tension often traces to an unbalanced pulley.

Q: What are the standard V-belt sections used in Australia?

Classical (imperial): Z (10mm top width), A (13mm), B (17mm), C (22mm), D (32mm), E (38mm) — Z and A are common on domestic and light industrial, B and C on general industrial, D and E on heavy industrial and mining. Wedge / narrow metric: SPZ (10mm), SPA (13mm), SPB (17mm), SPC (22mm) — the industrial default for new drives, higher power capacity than classical in the same envelope. Cogged variants (XPZ, XPA, XPB, XPC and equivalent) improve flexibility and let smaller pulleys be used. Poly-V ribbed belts (PJ, PK, PL, PM) suit high-speed compact drives. Match the section to the drive power, speed, and available pulley diameter — Gates, Fenner and other manufacturers publish selection charts by kW and RPM.

Q: Which brands of pulleys does AIMS stock?

AIMS stocks industrial pulleys from Finer Power Transmission (Australian PT distribution — full range across taper lock, bored-to-size, and stock pulleys) and other industrial suppliers. V-pulleys, timing pulleys, idler pulleys and taper lock bushes are stocked in standard classical and metric sizes. For heavy industrial and specialty pulleys (large diameter, high power, custom bore), contact AIMS for indent supply. See the V-pulleys, timing pulleys, idler pulleys and taper lock bushes for the full range. Matching belts in the belts range. For selection help read our pulley types guide and pulley speed ratio guide.