Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number RFM20C04 found under Nut Self Locking Pl by Republic Fastener Mfg Corp. The National Stock Number assigned to this part is 5310007646596, 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 RFM20C04.