Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 12-2164-2MKY found under Nut Self Locking He by Treadwell Corporation. The National Stock Number assigned to this part is 5310014858392, 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 12-2164-2MKY.