Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number S300NA42KAK21421CNQB1 found under Screw Cap Socket He by 3 V Fastener Co Inc. The National Stock Number assigned to this part is 5305015523310, 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 S300NA42KAK21421CNQB1.