Idler Sprockets: Ball Bearing Idler Sprockets have sealed ball bearings with extended sprockets internal competition and setscrews for securing to 
the shaft.
Projection From Centerline – Because of dimensional variation among bearing manufacturers this dimension can vary greatly slightly when different brands of bearings are used. For those who have a crucial application please demand specific dimensions.
Inner Race projection has 2 set screws on long part to secure bearing to shaft.
“Basic Dynamic Rankings” calculated according to AFBMA standard for “Long Rating And Fatigue Existence For Ball Bearings”
Accurately machined, medium carbon steel sprockets and precision floor ball bearings are assembled to provide much duty idler for the most severe conditions. The bearings are pre-lubricated and sealed to preserve grease and exclude dirt and moisture. They are not re-lubricatable. The extended inner race with setscrew enables fastening to a pin or shaft without collars or spacing products. In addition, it provides clearance for the chain when bolting the sprocket right to a body member or tensioning device. A little sprocket for close quarters and a larger one for heavier service is offered in each pitch. If sizes apart from those listed are required, make sure you inquire for quotation.