Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number B837-520W found under Ring Bearing Inner by Astec Industries Inc. The National Stock Number assigned to this part is 3110012471055, and the Federal Supply Class is 3110 Bearings Antifriction Unmounted. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like B837-520W.