Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 57B 6144 2 found under Ball Bearing by Hartzell Propeller Inc. The National Stock Number assigned to this part is 3110014697084, 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 57B 6144 2.