Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number B4 2X9 5DIN7971A3P found under Screw Tapping by Din Deutsches Institut Fuer Norm. The National Stock Number assigned to this part is 5305121715807, and the Federal Supply Class is 5305 Screws. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like B4 2X9 5DIN7971A3P.