Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 12M-21 found under Pin Straight Headle by Metrex Valve Corp. The National Stock Number assigned to this part is 5315014688524, and the Federal Supply Class is 5315 Nails Machine Keys And Pins. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 12M-21.