Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 503904-6 found under Bearing Ball Duplex by Ashcroft Inc. The National Stock Number assigned to this part is 3110000593083, 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 503904-6.