A sprocket[1] or sprocket-wheel[2] is a profiled wheel with teeth, or cogs,[3][4] that mesh with a chain, track or other perforated or indented material.[5][6] The name ‘sprocket’ applies generally to any wheel upon which radial projections engage a chain moving over it. It is distinguished from a equipment in that sprockets should never be meshed together straight, and differs from a pulley for the reason that sprockets have teeth and pulleys are easy.

Sprockets are found in bicycles, motorcycles, vehicles, tracked automobiles, and other machinery either to transmit rotary motion between two shafts where gears are unsuitable or to impart linear movement to a monitor, tape etc. Maybe the most typical form of sprocket could be found in the bicycle, where the pedal shaft bears a big sprocket-wheel, which drives a chain, which, in turn, drives a small sprocket on the axle of the trunk wheel. Early automobiles were also largely driven by sprocket and chain mechanism, a practice generally copied from bicycles.

Sprockets are of various designs, a maximum of efficiency becoming claimed for each by the originator. Sprockets typically do not have a flange. Some sprockets used with timing belts have flanges to keep carefully the timing belt centered. Sprockets and chains are also utilized for power transmission in one shaft to another where slippage isn’t admissible, sprocket chains becoming used instead of belts or ropes and sprocket-wheels rather than pulleys. They may be operate at high speed plus some forms of chain are so constructed concerning be noiseless also at high speed.