Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 44B3521-747 found under Nut Self Locking Hexagon by Carrier Corporation. The National Stock Number assigned to this part is 5310011774502, and the Federal Supply Class is 5310 Nuts And Washers. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 44B3521-747.