A slotted screwdriver is a tool used to apply torque to screws using a flat tip. Torque is the pressure applied when a device is turned clockwise or counterclockwise into place. This type of tool is designed to fit into slotted screw heads, which feature a single diveted flat impression on top of the screw. The device may be powered manually or by a motor.
The slotted screw design is often used in woodworking and fine jewelry making. The work that occurs in these types of industries is usually performed by hand, allowing the slotted screw to be easily tightened or removed. Other manufacturing industries tend to favor the Phillips head and the Torx® head, among others, both of which perform better when tightened with a power tool. Motorized drills tend to slip easily from slotted screw heads, potentially causing damage to the surrounding surfaces.
There are two types of slotted screwdriver primarily in use: keystone and cabinet. Keystone screwdrivers have slightly widened blades that narrow towards the flattened end of the driver. Cabinet drivers possess straight edges that form right angles with the blade edge. This type of screwdriver is often used for smaller screw work, like that which can occur in jewelry and watch making.
The slotted screwdriver may be operated manually or by an electric motor. Manual drivers feature a long, cylindrical handle, generally made of plastic, that fits into the palm of the hand. Motorized drivers are typically powered using a rechargeable onboard battery, or by means of an electrical cord that plugs into a socket. The head of this type of drill is typically interchangeable so that multiple driver ends or drilling bits may be used. Most drills are sold with a slotted and a Phillips head, and users may purchase additional bits depending on their personal needs.
Some versions of the slotted screwdriver are designed to perform additional tasks as well. The tester screwdriver, which is shaped identically to the slotted model, can be used to check for an electrical current through exposed wires. The flat headed tip of the driver can be placed against an exposed wire or piece of metal used to secure the wire. When current is running through the circuitry, a light flashes in the handle of the driver, alerting the user that the area is hot. Some tester screwdrivers can also be programmed to indicate whether the current is hot or used for grounding.