Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 3581-6 found under Tang Breakoff Tool Screw Thread by Armstrong Precision Components Ltd. The National Stock Number assigned to this part is 5120007117475, 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 3581-6.