Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 28-503 found under Press Arbor Power Operated by Jsj Corporation. The National Stock Number assigned to this part is 3442010044370, and the Federal Supply Class is 3442 Hydraulic And Pneumatic Presses Power Driven. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 28-503.