Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 511K2 found under Bearing Washer Thru by Yale Industrial Products Inc. The National Stock Number assigned to this part is 3120012748163, and the Federal Supply Class is 3120 Bearings Plain Unmounted. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 511K2.