Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number H18-457 found under Ring Piston by Dresser Industries Inc. The National Stock Number assigned to this part is 4310001420704, and the Federal Supply Class is 4310 Compressors And Vacuum Pumps. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like H18-457.