English pitch timing pulleys mate with same-pitch timing belts in synchronous drives. Timing pulleys are used in power transmission systems where maintenance of speed ratio is an important design consideration. These synchronous belt drive systems are durable, highly efficient, and suitable for many different applications. English pitch timing pulleys have a spacing or pitch based on inch (in.) measurements and a toothed, trapezoidal form. Pitch is the distance from one tooth’s center to the adjacent tooth’s center. Force is transmitted via evenly spaced grooves which mate with the teeth in the belt.