1/4" x 2-1/2", Stainless steel

US Fasteners

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.
Machine screw

Machine screws

Screws with machine threads for use with a nut or in a tapped hole.
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.
Set screw

Set screws

Screws with no head and machine threads for use in a tapped hole.
Hanger bolts & Dowel screws

Hanger bolts & Dowel screws

Hanger bolts and dowel screws are used for adding an external machine or screw thread to wood applications.
Elevator bolt

Elevator bolts

Bolts with a very large flat head and machine threads for use with a nut.
Cotter pin

Cotter pins

Cotter or split pins have two tines which are bent apart to hold them in place.