This Boston Gear PLB series timing pulley has either a 3 mm or 5 mm pitch, and is suitable for use with 9 mm wide curvilinear tooth belts in power transmission applications that require synchronous rotation. This polycarbonate resin thermoplastic pulley has an aluminum insert with a 0.375" bore diameter and mounts to a drive shaft using setscrews. The fiberglass-reinforced polycarbonate resin thermoplastic provides light weight and low noise. Timing pulleys are a type of drive pulley and are used in a wide range of mechanical and electronic drives, including automotive and printing industries.

Pulley drive systems consist of two or more pulleys that connect with a belt to transmit mechanical power across greater distances than systems that use gears. Pulleys (sheaves) are available in different types: V-belt, timing, round, or flat. Pulleys must match the belts that connect them (timing pulleys with trapezoidal grooves require a belt with trapezoidal teeth) and engage either on the sides of the pulley flange (classical V-belts, narrow V-belts, or round belts), on the flat outer diameter of the pulley (flat belts), or in pulley grooves that match belt teeth (timing belts, synchronous belts, or curvilinear belts). Pulleys are made of various materials, including cast iron, steel, aluminum, polycarbonate resin thermoplastic, and nylon, and they can meet a broad range of requirements, including increased torque, resistance to wear, and light weight. Pulleys are used in drive designs in the automotive, appliance, agriculture, textile, printing, mining, and office equipment industries.

Boston Gear manufactures gears, gear drives, bearings, valves, shaft collars, couplings, and other power and fluid transmission components. The company, founded in 1877, is headquartered in Charlotte, NC, and meets International Organization for Standardization (ISO) standard 9001:2008 standard.