Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number F31-5 found under Heater Overload by Challenger Electrical Equipment Corp. The National Stock Number assigned to this part is 6110009917000, and the Federal Supply Class is 6110 Electrical Control Equipment. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like F31-5.