Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 643673118 found under Shaft Shouldered by Duffnorton Co Inc. The National Stock Number assigned to this part is 3040012842270, and the Federal Supply Class is 3040 Miscellaneous Power Transmission Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 643673118.