Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number HC4138 found under Pin Straight Headless by Raytheon Company. The National Stock Number assigned to this part is 5315001804875, 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 HC4138.