How to choose screwdrivers.

There is a range of screwdrivers that a general DIYer should have in their toolbox. Which one they use is determined by the type of screw head they are about to work with and the space in which the screw is to be accessed.

The most common types of screw heads are:-

Flat Head Screws

Flat head screws are the original screw. Today they are usually reserved for decorative screws or screws that will be seen when a job is finished. e.g. the black round headed screws you find on gate bolts or internal wall fixtures. They were superseded in general construction by other screws because flat head screws become easily damaged in use making them difficult to drive in to place and prone to causing the screwdriver to slip off the head resulting in damage to the the surrounding decorative surface.

Phillips or Cross Head Screws.

Phillips or cross head screws have a simple crossed slot for the appropriate sized cross head screwdriver. They overcame the problem of screwdrivers slipping or damaging the screw head. The are typically used with wood and countersunk in that they drive into the wood so that the top of the screw is flush with the wood. The size of the screwdriver bit that should be used with cross head is denoted by the prefix "ph".

Posidrive Screws

Posidrive screws are seen as an improvement on crosshead in that they have 4 small extra slots in the head to provide an even more secure fit for screwdrivers and probably as a result of the increasing use of electric screwdrivers which deliver more torque than a cross head can handle before it slips. Posidrive screwdriver and screws and denoted by the "pz" prefix. It is important to use posi with posi only.

Torx.

Torx screws usually found in small electrical equipment such as DIY power tools or computers. As a rule if it is a torx head steer clear as the area beneath requires specialist knowledge.

Hex or Allen.

Hex and Allen Screws are usually found in flatpack furniture construction. It is possible to buy sets of hex keys in both imperial and metric sizes, they are useful to have but most flatpack will have a throw away allen key provided.

Other Factors

Apart form the head type, screwdrivers have other characteristics determined by their specific intended use.

  • Stubbu Screwdriver with a philips head.Short & stubby, flexible or angled drivers for confined or awkward spaces. Whilst they can over come a problem it is difficult to apply much torque or power to the screw.
  • Very long screwdrivers to get at that hard to reach screw but hard to control the end as the screwdriver get longer.
  • Ratchet Screwdrivers are convenient making it easy and quicker drive or remove screws. Most ratchet screwdrivers come with a range of interchangeable screw heads reducing the number of screwdrivers you need to buy. The ratchet screwdriver below comes with a range interchangeable heads as well as some small sockets.

 

 

  • Buying cheap screwdrivers is a false economy. Not only will they wear out quickly but they will be likely to break on a sunday evenining when the shops a shut and your DIY project is spread out all over the kitchen table! Buy from a reputable source brand and your scredrivers should last a long time.