Brewer Idler Sprockets

Brewer's 49 idler sprockets cover ASA chain sizes 25, 35, 40, 50, 60, and 80. Reading the part number tells you the spec: 50B17U decodes as ASA 50 chain, B-style hub, 17 teeth, U-suffix bronze bushing. Once you know the chain size, tooth count, and bearing preference, the part number practically writes itself.

Tooth count selection is driven by your drive geometry. More teeth (typically 17 to 19) give smoother chain engagement, reduce chordal action, and extend chain life. Fewer teeth (11 to 13) work in tight installations where the larger sprocket would not fit. Brewer publishes both ends of the range across most chain sizes.

Three bearing options. Bronze bushing (U-suffix) is the most common at typical industrial speeds and is what you want unless you have a reason to upgrade. Needle bearing (F-suffix) cuts friction and is the right call for high-RPM or extended-duty positions. Nylon composite (N-suffix) is for lighter loads where weight reduction or quiet operation matters more than raw load capacity.

B-style sprockets have a hub for use with a bushing. D-prefix parts (D40B19U, etc.) are the double-width versions for double-strand chain. Need a cross-reference from Browning or another manufacturer? Call us with the part number and we will pull the equivalent.