Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 57993 found under Screw Tapping by Thor Power Tool Co Sub Of Stewar. The National Stock Number assigned to this part is 5305009473619, 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 57993.