Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number M-4-2-7 found under Screwcapsocket Head by Rolls Royce Marine North America. The National Stock Number assigned to this part is 5305016826381, 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 M-4-2-7.