Idler Sprockets: Ball Bearing Idler Sprockets have sealed ball bearings with extended internal race and setscrews for securing to the shaft.
Projection From Centerline – Due to dimensional variation among bearing manufacturers this dimension can vary greatly slightly when different brands of bearings are used. For those who have a critical application please call for specific dimensions.
Inner Race projection provides 2 set screws on long part to secure bearing to shaft.
“Basic Dynamic Ratings” calculated according to AFBMA regular for “Long Ranking And Fatigue Life For Ball Bearings”
Accurately machined, medium carbon steel sprockets and precision surface ball bearings are assembled to provide much duty idler for the the majority of serious conditions. The bearings are pre-lubricated and sealed to maintain grease and exclude dirt and moisture. They aren’t re-lubricatable. The extended internal race with setscrew enables fastening to a pin or shaft without collars or spacing gadgets. It also provides clearance for the chain when bolting the sprocket right to a framework member or tensioning gadget. A little 
sprocket for close quarters and a larger one for heavier provider is supplied in each pitch. If sizes other than those listed are necessary, make sure you inquire for quotation.