Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 17 4PH CONDITION A found under Bar Metal by Ducommun Metals Co. The National Stock Number assigned to this part is 9510011415077, and the Federal Supply Class is 9510 Bars And Rods. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 17 4PH CONDITION A.