ChinaFinishedBoreSprocket A sprocket idler is a sprocket with built-in bearings. Its main functions include changing the steering of the driven wheel, tensioning the chain, and adjusting the pressure angle.The idler gear is a part of the gear train that plays a transitional role and will not change the transmission relationship. It is to make the force of the gear train more reasonable or to meet the layout of the entire transmission system. Only sprockets and chains of the same specification can be used in combination. This series is ISO standard 04C/ 06C/ 08A/ 10A/12A/16A (ANSI standard 25B/ 35B/ 40B/50B/60B/80 sprocket idler, do not use with 04B/ 05B/ 06B/ 08B/ 10B/ 12B/ 16B series sprockets and chains, it may cause the chain sprocket mechanism to not work properly! Advantage of idler sprockets is apply tension to the chain to prevent chain vibration, noise and poor meshing of sprockets. Material of the idler sprocket can be steel, nylon, plastic and stainless steel. Idler sprocket dimensions can be made according to customer鈥檚 requirements, drawings or samples. ChinaFinishedBoreSprocket website:http://www.tjondgear.com/sproc....ket/finished-bore-sp