Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number W4-B-419 found under Retainer Ball Beari by Harding Safety Usa Inc. The National Stock Number assigned to this part is 3110013141834, 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 W4-B-419.