BIS Certification for Double-pitch precision roller chains and sprockets IS 15509 BIS Certification for Double-Pitch Precision Roller Chains and Sprockets for Transmission and Conveyors is conducted under IS 15509:2017. This has been developed for the quality, performance, and interchangeability intended for roller chains and sprockets used for industrial transmission and conveyor systems. This standard adequately outlines the requirements for dimension, material, and manufacture accuracy for the mechanical properties needed for seamless power transmission and for the effective operation of the conveyor. The standard also describes the other needed properties for operational reliability and the wear, noise, and other performance enhancements concerning the life of the equipment used in the system. BIS Certification is thus the proof of conformity for the manufacturer and the uninterrupted chain and sprockets for the Indian market. The industry and the equipment manufacturer thus comply with the IS 15509:2017. Presence of the ISI mark on the double pitch roller chains and sprockets shows conformity and thus promises the reliability, exactness and all the consistency needed of the equipment under the industrial pressure.