
Precision forging of straight bevel differential gears, helical gears, diff lock clutches and other powertrain parts all fully machined to customer specifications. Precision forged bevel teeth require no other machining on the tooth profile and we are capable of forging to as low DIN 7 and its AGMA equivalent.



SDP/SI - Stock Drive Products/Sterling Instrument is a U.S.-based manufacturer of power transmission and motion control products, serving customers since 1950. The company specializes in precision gears, high-quality mechanical components, gearboxes, and the assembly of both mechanical and electromechanical subassemblies. SDP/SI is part of the Designatronics family of brands, offering a wide range of stock mechanical component options and customized solutions to meet diverse engineering needs.