Screwdrivers are indispensable for DIY. They will vary in design and size to correspond with different screw types and sizes. Basically there are two types of screwdriver: slot-headed and cross-headed.
Slot-headed screwdrivers have flat tips which can be flared or parallel. A flared tip is stronger and allows you to apply extra torque (rotational force). A parallel tip will align with the diameter of the screwdriver’s shaft. This allows you to drive a screw beneath the surface of the timber without getting the tip of the screwdriver wedged in the timber, which can be a problem with a flared tip.
Cross-headed screwdrivers will have a cross-shaped tip that may be pointed or flat. Generally, smaller cross-headed screwdrivers will have pointed tips and larger cross-headed screwdrivers will have flat heads. Cross-headed tips fit more securely into the head of he screw allowing you to use much greater rotational force. There are two types of cross-headed screwdrivers: Phillips and Pozidrive.
The tip of a Phillips cross-headed screwdriver viewed in cross-section has a simple cross design. The tip of a Pozidrive cross-headed screwdriver is very similar, but it has an additional projection between each cross-projection to give extra grip.
A ratchet screwdriver can be used without having to adjust your grip. A three-point switch can be set for different functions. When the switch is set in the central position the handle is locked and the tool can be used as an ordinary screwdriver. The other two settings allow you to turn the handle clockwise or anti-clockwise.
Pump-action screwdrivers are very popular as they can be used without having to alter your grip on the handle. A spring-loaded shaft moves in and out of a hollow handle which is fitted with a ratchet mechanism. A three-point switch controls the rotation of the shaft. Pushed to one side the shaft will rotate to drive the screw. Pushed to the opposite side the shaft will rotate to unscrew the fixing. When the switch is positioned centrally, the shaft locks to allow it to be used as an ordinary screwdriver.
Cordless electric screwdrivers make working much easier. Operated by a rechargeable battery, electric screwdrivers can be set to drive in and remove fixings. Electric screwdrivers are very versatile as they come with a large selection of interchangeable heads, both slot-headed and cross-headed, that fit into the end of the shaft.
Designed to fix screws in awkward areas, the stubby screwdriver has a short shaft. They are available with either slot-headed or cross-headed tips.
- Always use the appropriate screwdriver for the fixing.
- The screwdriver should be held at right angles to the screw head.
- The tip should fit securely into the screw head before you start turning.
- Turn the screwdriver clockwise to drive in the fixing.
- Turn the screwdriver anti-clockwise to remove the fixing.