Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number A51B43500-15 found under Bearing Sleeve by B And B Precision Components Inc. The National Stock Number assigned to this part is 3120012641666, 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 A51B43500-15.