Idler Sprockets: Ball Bearing Idler Sprockets have sealed ball bearings with extended inner 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. Should you have a 
critical application please demand specific dimensions.
Inner Race projection provides 2 set screws on long side to secure bearing to shaft.
“Basic Dynamic Rankings” calculated according to AFBMA regular for “Long Ranking And Fatigue Life For Ball Bearings”
Accurately machined, medium carbon steel sprockets and precision ground ball bearings are assembled to supply a heavy duty idler for the the majority of severe conditions. The bearings are pre-lubricated and sealed to keep grease and exclude dirt and moisture. They aren’t re-lubricatable. The extended inner race with setscrew enables fastening to a pin or shaft without collars or spacing devices. In addition, it provides clearance for the chain when bolting the sprocket directly to a body member or tensioning device. A small sprocket for close quarters and a larger one for heavier services is offered in each pitch. If sizes apart from those listed are necessary, please inquire for quotation.