2-1/4", US, 18, 18-8

US Fasteners, 2-1/4", 18, 18-8
Hex bolts Bolts with hexagonal heads and machine threads for use with a nut or in a tapped hole. Also known as hex cap screws or machine bolts.	Machine screws Screws with machine threads for use with a nut or in a tapped hole.
Eye bolts & Screw eyes Bolts or screws with a circular ring on the head.	Shoulder bolts Screws with an unthreaded shoulder that is larger in diameter than the threads. Also known as stripper bolts.
Elevator bolts Bolts with a very large flat head and machine threads for use with a nut.