Similar with bolts, screws are also a major category of threaded fasteners. Screws and bolts share a lot of likenesses such as being made of metal and being characterized by a helical ridge. They are both used to fasten materials by the engagement of the screw thread or the external thread with a similar internal thread in the matching part.

Truly, screws and bolts are hard to differentiate with the naked eye. They are both threaded materials and have a head for tightening the fastener, but the most obvious difference is that a bolt is not usually threaded all the way along its shank as it has a plain portion. On the other hand, a screw is threaded fully to the head.

Generally, screws don’t need nuts to get fastened. They become secure by being tightened into the hole using a screwdriver. Screws are usually shorter than the width of the material being screwed and don’t protrude on to the other side.

Sockets are gears for attaching a turning tool to lock fasteners. They fit over the head of the fastener to provide torque. Fasteners such as socket screws, also known as Allen Head screws, have sockets within their heads so that Allen wrench could secure the screw.