1/4" x 8"

US Fasteners

Sheet metal screw

Sheet metal screws

Screws with large threads for use in sheet metal sometimes also used in plastic, fiberglass, or wood.
Hex bolt

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.
Carriage bolt

Carriage bolts & Plow bolts

Bolts with no drive, and machine threads for use with a nut.
Lag bolt

Lag bolts

Large wood screws technically called lag screws.
Socket product

Socket screws

Screws with an allen wrench drive.