Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number LK21090-350 found under Screw Machine by Torkon Fastener Corp. The National Stock Number assigned to this part is 5305001440547, 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 LK21090-350.