Bolts

Bolts use a wide variety of head designs similar to those used for screws.

Nuts

Nuts are a small metal object with a corrugated hole in the middle.

Washers

Washers are a machine component that is used in conjunction.

Screws

A screws and a bolt are similar types of fasteners typically made of metal.

Thread/Studd

A threaded rod, also known as a stud, is a relatively long rod.