What Is an Electric Screwdriver?
An electric screwdriver is a power tool where the motor handles the rotating action necessary for tightening screws. This tool significantly saves time and labor in screw-tightening tasks compared to manual methods. Electric screwdrivers can be broadly categorized into drill screwdrivers and impact screwdrivers.
Drill drivers are adept at high-speed fastening and offer adjustable rotation speeds for precision work. They can double as drills when fitted with the appropriate bit and often feature a clutch mechanism to prevent over-tightening. On the other hand, impact drivers, known for their striking power, combine rotational force with impact to achieve greater torque, allowing for efficient fastening without pre-drilling.
Uses of Electric Screwdrivers
Electric screwdrivers are widely used for fastening a large number of screws, particularly in industrial assembly plants. While many factories use air-powered screwdrivers, electric ones are also common, especially on construction sites. Impact drivers are particularly useful in construction, capable of driving screws into thick wood without pre-drilling, making them handy for various DIY projects.
Principle of Electric Screwdrivers
Electric screwdrivers operate by using electricity to power a motor that rotates the bit for screw driving. They can be either corded, connected to an outlet, or cordless, powered by batteries. Cordless models offer portability and convenience, especially on construction sites where mobility is essential.
1. Drill Driver
Drill drivers feature adjustable rotation speeds controlled by a trigger. The depth to which the trigger is pulled determines the speed, allowing for both slow and fast rotations. They also often include a clutch mechanism to regulate the tightening torque, preventing over-tightening by slipping at a predetermined torque.
2. Impact Driver
Impact drivers incorporate a hammer mechanism that delivers rotational momentum as an impact force, enabling high torque generation. However, unlike drill drivers, they cannot adjust rotation speed or limit tightening torque.
Additional Information on Electric Screwdrivers
1. Bits for Electric Screwdrivers
Electric screwdrivers are versatile, with the ability to fasten various screw types by attaching different bits. Drill screwdrivers can also be used for drilling when fitted with the appropriate drill bit. The selection of bits should align with the specific use of the electric screwdriver.
2. Bit Hardness
Bits are categorized into hardness levels (S, E, G, H, X), with X being the hardest. The bit’s hardness should match the screw’s hardness to avoid damage during fastening.
3. Length of Bit Insert
Bit inserts vary in length, typically classified as A-type (used in domestic screwdrivers) and B-type. The selection of the bit insert length should be compatible with the specific electric screwdriver model.