Draper 24639 Expert 3mm x 100mm Fully Insulated Plain Slot Screwdriver. (Display Packed)
Draper 05721 Expert 10 Piece VDE Approved Fully Insulated Interchangeable Blade Screwdriver Set
The first screwdrivers had a long metal shaft and flat head fitted to a wooden handle. This basic tool came in a range of sizes to suit the screws of the day. To overcome the problem of damaged screw heads the cross head screw was developed , and then evolved into a deeper version requiring a new type of screwdriver. The Phillips type screw then evolved into a more advanced type known as the Pozidriv system. Pozidriv is similar to Phillips but does not come out as easily so is better for power tools. Sadly Phillips and Posidriv are not totally compatible and using the wrong driver can damage the screw and make it very difficult to remove.
For screws that can take a lot of torque or will be removed frequently, the Hex screw drive is another system and commonly known as Allen drive. The 6 sided hexagon heads are used more on machinery and in engineering than Philips or Pozidriv screws which are more useful in woodwork and building.
If this was not complicated enough yet another type of screw fixing system has become popular and also uses a 6 sided design, this time a star. The Torx fitting was developed to reduce tampering by users of equipment and is frequently found in electronics and in domestic goods.
So to fully equip a workshop will require four or five sets of screwdrivers. As well as the type of screwdriver it is also useful to have shorter shafted screwdrivers known as stubbys.
Stanley are the most well known maker of screwdrivers and developed the excellent pump action screwdriver that was very popular before the invention of the cordless drill driver.
Multi headed, "all in one" screwdrivers
With so many systems of screw fitting it would seem that having one driver handle and shaft that can use a multitude of small heads from all the systems is a great idea.
Whilst they sound like a good idea they do have drawbacks. Most all in one screwdrivers use standard bits but to enable them to be held on the tool the shaft has to be thicker than that of a standard screwdriver. This can be a problem when working with restricted access.
To speed up screwing action a ratchet mechanism can be used and is available on conventional and multi headed screw drivers. Ratchet screwdrivers more susceptible to failure so the cheaper versions may not be suitable for use where high torque is required.
Knock through screwdrivers
It is common for screws of all types to corrode and refuse to move. A solution to this is to tap the handle of the screwdriver to nudge the screw loose. Most screwdrivers are not designed to be hit with a hammers so may break during this process. A knock through or strengthened screwdriver has metal caps and hardened tips to cope with this problem