Pulleys driven by endless rubber V-belts were first standardised in 1917 (by the Gates Rubber Company of Colorado) and are now basic power transmission components in a vast range of machinery, including mowers, vehicles, pumps, cement mixers, compressors, printing and paper-making machinery and conveyor systems. V-belts themselves come in a range of sizes, profiles and configurations. The most common metric profiles are designated SPA, SPB, SPC and SPZ (also sometimes referred to as wedge or narrow profiles).

The pulleys listed in this section are SPB section aluminium pulleys with a single groove. They are of a solid aluminium construction, without weight-saving cut-outs, and have a solid hub so that they can be bored or machined to suit the mounting of your power-transmission machinery. The drillable centres are pre-marked with a centre point to assist you in this.

Although "classical" or imperial V-belts have sides angled at 40 degrees whilst those of this metric series are at 34 degrees, pulleys often have a degree of tolerance to the belts running on them. Thus you may be able to use a "classic" or imperial B cross-section belt in place of an SPB on these pulleys, but it will ride higher in the groove and its load tolerance and slip resistance will not be identical. If in any doubt about matching pulleys and belts, Simply Bearings personnel are always available and happy to offer expert advice.

Modern metric cross-sections can generate as much as double the horsepower of older classic belts and pulley systems with the same belt top width. However, as always, it's important to adjust the pulley-to-pulley distance to establish the optimum tension in the belt for maximum energy-efficiency and overall performance.

SPZ, SPA, classic, extra-narrow, multi-groove and other types of pulley and matching belts are available in other sections on the Simply Bearings website, as are pulleys constructed in other materials, such as cast iron, stainless steel or with zinc alloy coatings for additional corrosion and weather resistance. (On request, we can source any type of pulley not currently listed.)

Our SPB section aluminium pulleys are lightweight, hard-wearing, corrosion-resistant and guaranteed to be reliable. They are also precision-engineered to eliminate vibration or pulsing at high speeds. They comply with ISO 4184 and a variety of other international quality standards.

Metric V-belts and pulleys are usually specified by letters to denote the SP section, with the following numbers denoting the pitch length (in millimetres). Check the "Technical" section of the product description to confirm the hub and pulley inner and outer diameters match your precise requirements.

We can usually provide same-day dispatch and free shipping within the UK and moderate rates for express and international shipping.