Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 511503 found under Socket Plate Assemb by Apex Tool Group Llc. The National Stock Number assigned to this part is 2895016504924, and the Federal Supply Class is 2895 Miscellaneous Engines And Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 511503.