Brewer Machine & Gear Co. 50B17F is a needle-bearing idler sprocket designed for 50-chain drives (5/8 in pitch). It is a B-style, single-width idler with 17 teeth and a 1.000 in bore, produced in steel for use with 1‑strand 50 chain systems. This sprocket guides and tensions roller chain in power-transmission and material-handling equipment, maintaining proper chain engagement with the drive sprocket and controlling slack in the chain path. The 50B17F designation appears in Brewer’s catalog and distributor listings for 50‑pitch, 17‑tooth, 1‑inch‑bore idlers with needle bearings, reflecting its role within Brewer’s line of sprocket idlers and tensioner components.
