Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number HB8-5 16-18X18 found under Screw Cap Socket He by Flowserve Corporation. The National Stock Number assigned to this part is 5305013970379, 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 HB8-5 16-18X18.