Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 4000-5375 found under Screw Cap Socket Head by Cincinnati Steel Treating Company. The National Stock Number assigned to this part is 5305016216313, 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 4000-5375.