Idler Sprockets: Ball Bearing Idler Sprockets have sealed ball bearings with extended inner race and setscrews for securing to the shaft.
Projection From Centerline – Due to dimensional variation among bearing producers this dimension may vary slightly when different brands of bearings are used. In case you have a crucial application please call for specific dimensions.
Inner Race projection offers 2 arranged screws on long part to secure bearing to shaft.
“Basic Dynamic Rankings” calculated according to AFBMA standard for “Long Ranking And Fatigue Existence 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 are not re-lubricatable. The extended internal race with setscrew allows fastening to a pin or shaft without collars or spacing gadgets. It also provides clearance for the chain when bolting the sprocket directly to a frame member or tensioning device. A small 
sprocket for close quarters and a larger one for heavier provider is provided in each pitch. If sizes apart from those listed are required, make sure you inquire for quotation.