The electric screwdriver is a common home maintenance tool that is built from the same type of materials that most power tools are made from: plastics and metals. Portable electric screwdrivers also include rechargeable batteries made from chemicals such as a nickel-cadmium compound. Small amounts of circuitry are also often incorporated into newer models to control torque and electrical flow, which is built upon a silicon circuit board.
The same type of plastic used to make electric screwdrivers is also often used to make many other commercial products, such as DVDs, bottle lids and automotive parts. The plastic has to be somewhat flexible so that it does not crack or shatter on impact and durable against climate conditions, oil spills and other conditions in the outdoors or a workshop setting. Polystyrene and polypropylene are two of the most common plastics used for power tool housings that have these traits.
The three most common types of metal used in an electric screwdriver are steel, aluminium and copper. Steel is used to make the gears, clutch assembly and bits because of its superior strength. Aluminium is used for the interior housing for its lightweight, durable qualities. Copper is used to make the windings for the electrical motor and other electrical wiring connections for the tool.
Silicon is used as a circuit board base in many modern electric screwdrivers. Transistors and other electrical components are built onto a silicon wafer base. The circuitry acts as a form of advanced control system to keep the power level of the tool at exactly the right point. The controller also acts to cut or reduce power to the motor as the level of desired torque is reached in the tool so that components are not overstressed and damaged.
Rechargeable batteries are a key component of any cordless electric screwdriver. They are usually made from one of three types of compound mixtures. A nickel-cadmium (NiH) battery was the most common until recently. Newer battery designs use nickel-metal hydrides (NiMH), which give a longer-lasting charge to the battery and are easier to dispose of, as they are less detrimental to the environment. Lithium ion (Li-Ion) batteries are another common type used, but they can lose their ability to recharge if fully discharged.