Screw Types

Posted by gewharvey 14/04/2023 0 Comment(s)

Depending on size, thread, tip and head, different screws are used more effectively for different purposes. The head and drive tpre of a screw are the ley determining factors of the torque and strength, so you want to make sure that the correct screw is used for it's purpose, Thhis guide provides some information on helping you make that chouce.


Screw Head and Drive

Hex Head Screws

As the name suggests, these screws have a hexagon shaped head that do not have any slots for a screwsriver. They are the perfect choice for fastening together pieces of metal and can be tightened using a socket wrench. They come available most commnly in a grade 8.8 finish that is considered high tensle, but we have a selection of 10.9 and 12.9 available for higher strength requirements. Commonly referred to as 'set screws' as they are fully threaded as opposed to hexagon bolts that are partially threaded.

Phillips Screws

The most commonly used type of screw with two slots in the head that for a cross shape. These are designed so that the screwdriver doesn't slip during use, but don't require a lot of torque to install. Mostly used for joining wood together.

Pozidriv Screws

These are similar to the above Philips screws, but have 8 slots in the top allowing for a higher torque. Ideally used when the fixing material required a tight hold as these guarantee a good fixing finish.

Slotted Screws

Slotted screws have a single slot in the head that goes from one side to the other, and are great for joingin two pieces of wood together. These are recommended for use with low-medium torque requirements.

Socket Screws

Socket screws use a hexagon hole in the mddiel so they can be tightened using a 'hex' or 'allen' key. These allow for a greater torque fixing. The three most common head types are a button (dome), countersunk or cap head. Manufactured in 10.9 or 12.9 grade steel.

Torx Drive

Torx screws have a shape in the head that resembles a six sided star. These allow for a greater torque strength. There is also a security version for secure environments that incorporates a pin in the centre of the star so common drivers will not fit to release the fixing.


Screw Usability

Plasterboard Screws

These are usually supplied with a metal plus that screws into the plasterboard with a large pitch thread. The screws used to fix material down are then driven into these plugs. Depending on the fixing material, plasterboard screws with a trumpet head can be used without the plug. These have a strong torque fixing, but not a forceful impact. These can come with a sharp, perforated or self-drilling tip.

Self-Drilling Screws

Self drilling screws do not require the drilling of a pilot hole to be installed. Theses screws, that are most commonly found on facades and roof producs such as purlins. They are often supplied with an EPDM washer that seals the bottom of the head against the fixing material to prevent water ingress.

Security Screws

Security screws come in a variety of head styles that une non-uniform tooling. The purpose of these is that the screws can then not be removed by anyone without the correct tooling making them ideal for areas that need to be securely held down. The required tooling is usually not available from merchants that do not sell those screws.  A number of these screw types are also permanent meaning that they can not be removed at all.

Standard Screws

This includes all standard screws that are made to predetermined specifications, usually set by either the DIN or BS standard. These standards provide exact details on all the dimensions of a screw and regulate, for example, that the head diameter n each size screw is also the same, not matter the manufacturer.

Wood Screws

Wood screws, of which coach screws are the most common type with a hexagon head, have a large thread pitch that provides a stronger more secure hold. Caps of multiple colours can be used to decorate if the screw head will be on show.