, also known as engineered sprockets, engineering class sprockets, or mill sprockets, are gears used in conjunction with conveyor belts and chains
. The profiled wheels or toothed gears mesh with the conveyor belt or chain resulting in rotary motion. Commonly available conveyor sprockets include the quintuple, quadruple, triple, double and single mill sprockets. Usually, there are four types of standard hubs and two types of specialty hubs. Standard hubs are mostly designated as type A to type D depending on the location of their hubs. Specialty hubs include tapered bushings
with a tightened down shaft allowing it to minimize shaft marring and shear pin with hubs designed to provide protection against overload and system jamming. Specifications to consider when purchasing a conveyor sprocket include bore diameter, hub diameter, number of teeth, weight, speed, and noise generation. Typically, plastic hubs are quieter but suitable only for light and medium duty applications. Steel, stainless steel and hardened steel are also used to make hubs.