Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 6645258-5 found under Bearing Pinion by Dresser Rand Co. The National Stock Number assigned to this part is 3110003994002, 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 6645258-5.