Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number ANS13-8X1-16UNCB18-2-1-81 found under Screw Cap Socket He by American Society Of Mechanical. The National Stock Number assigned to this part is 5305013345331, 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 ANS13-8X1-16UNCB18-2-1-81.