Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 9-4256 found under Adapter Socket Wrench by Sears Roebuck And Co. The National Stock Number assigned to this part is 5120002278095, and the Federal Supply Class is 5120 Hand Tools Nonedged Nonpowered. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 9-4256.