5/16" x 1-3/4", US, Stainless steel, External hex

US Fasteners, 5/16" x 1-3/4", Stainless steel, External hex
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.	Lag bolts Large wood screws technically called lag screws.