An electric screwdriver is a portable electric device that allows you to screw and unscrew effortlessly. The head of the screwdriver is equipped with a bit holder which can be magnetic or have a quick release system. The bit holder allows you to quickly insert the bit that corresponds to the screw head.
This guide applies only to electric screwdrivers, power tools that are portable and have only screwing and unscrewing functions. They must not be confused with driver drills.
Choosing the right electric screwdriver depends on what you will use it for. For example, will you be using it frequently for construction work? New buildings or renovations? In a mechanical workshop? For furniture? On an assembly station?
The second point it is important to define is the screwdriver’s frequency of use. If it needs to be used all day, it is better to choose a corded model. If it only needs to be used 2 or 3 hours a day, however, a cordless model might be appropriate, perhaps keeping an extra battery and a charger close by. It is important to pay particular attention to the screwdriver’s efficiency, especially if it needs to be used intensively.
The tightening torque is another point it’s important to consider. A high tightening torque means a strong screwing force. The higher the tightening torque, the easier screwing will be, even in hard material.
The tightening torque is directly linked to the power of the screwdriver. For mains powered corded electric screwdrivers, that power depends directly on the power of the motor. This varies between 450 and 705 watts. If the electric screwdriver is powered by an external transformer, the higher the supply voltage, the more powerful the screwdriver will be. For cordless electric screwdrivers, the power is linked to the battery voltage. This can go from 3.6 volts (V) to 18V for the most powerful ones. For cordless electric screwdrivers, a high voltage allows for a longer battery life and avoids having to recharge the batteries too often. Certain electric screwdrivers are called impact electric screwdrivers: they are used for intensive screwing/unscrewing.
The rotation speed is an essential element, especially if you need to use your electric screwdriver regularly: corded electric screwdrivers generally have a higher speed of rotation than cordless ones. Generally, electric screwdrivers only have one rotation speed. For corded electric screwdrivers, this is between 3,000 and 6,000 rpm (rotations per minute) and for cordless electric screwdrivers between 180 and 450 rpm. For impact electric screwdrivers, the speed is indicated in counts per minute: it is between 3,000 and 50,000 cps/min.
HOW TO CHOOSE
configuration of the elements to be screwed
frequency of use
What type of electric screwdriver should you choose: corded or cordless?
There are two main kinds of electric screwdrivers: corded ones, which are generally more powerful, and cordless models which run on batteries.
The weight of the electric screwdriver is an important factor to take into account. For the same power, corded electric screwdrivers are lighter than cordless electric screwdrivers. This is because the weight of cordless ones is increased by the battery.
There are 2 types of electric screwdrivers:
corded electric screwdrivers
cordless electric screwdrivers
Why choose a corded electric screwdriver?
A corded electric screwdriver allows for intensive use. They generally offer significant tightening torque. They also have the advantage of being lighter as they don’t have battery weight. You can choose a corded model if there is a power source available close to the zone where the electric screwdriver is going to be used.
A corded electric screwdriver is particularly adapted for use on an industrial assembly station, in a mechanical workshop, or when it is used in a restricted area. The advantage is that they can be used intensively. That said, the cord connected to the source of power can represent a constraint in terms of its length (access to all the parts to be screwed or unscrewed) or even an accident risk if it crosses a passage area.
Corded portable electric screwdrivers are generally designed to operate on a single-phase mains supply of electricity. Electric screwdrivers for assembly stations are generally supplied with 32 or 40 volts of direct current from the control box.
Why choose a cordless electric screwdriver?
A cordless electric screwdriver can by used in all kinds of environments. Battery-powered electric screwdrivers are easy to handle and can be used in areas without a source of power. They are limited by the autonomy and power of the battery.
Cordless electric screwdrivers are particularly well suited for furniture assembly because they make it possible to move around the various elements without restrictions. They are also widely used for fixing plasterboard, or for dismantling or assembling auto body parts. The battery power must be sufficient to guarantee the torque required for screwing however. It is recommended to have at least one spare battery so as not to be limited in autonomy.
For portable electric screwdrivers, you have to take into account the weight of the device with the battery, which can be around 2kg for a powerful electric screwdriver.
Generally speaking, cordless screwdrivers are equipped with lithium-ion batteries. These are the batteries that offer the best characteristics to date: they are lighter than other types of batteries and hold a charge better. The stronger the capacity of the battery, the more autonomous it is. Generally speaking there are three types of electric screwdriver batteries: less than 1.5Ah (ampere hour), between 1.5 and 2Ah and over 2Ah.
Cordless electric screwdriver characteristics:
their power is expressed in volt-ampere (VA). The more powerful a battery is, the more autonomy it will have and the higher the tightening torque will be.
the battery’s voltage gives an indication of the tightening torque: the higher the voltage, the higher the torque will be.
the battery’s capacity gives an indication of the autonomy: the higher the capacity, the greater the battery’s autonomy will be.
Which electric screwdriver design should you choose?
You can choose between three main models of electric screwdrivers:
Straight electric screwdrivers, which have the body in the screwing axis. These electric screwdrivers are well-suited for workstations where they can be suspended from a winding system and where the direction of screwing is from top to bottom. Some straight electric screwdrivers are designed to operate with digital control on automated workstations.
Pistol electric screwdrivers have an angled body for a better grip.
Right-angle electric screwdrivers allow you to reach screws located in tight areas.
electric screwdriver designs:
straight electric screwdrivers
pistol electric screwdrivers
right-angle electric screwdrivers
What options are available?
Some electric screwdrivers are equipped with a system for adjusting torque. They are able to disengage once the pre-defined torque has been reached, either because the screwing is complete or because the screw has jammed, thus avoiding transmitting the torque to the operator. This system can be mechanical or electronic.
The most advanced electric screwdrivers include electronic settings linked to external systems, which allow for very subtle adjustments. The most affordable electric screwdrivers on the other hand only offer mechanical adjustments for tightening torque and adapting speed. Some inexpensive electric screwdrivers don’t include any adjustment options.
Some electric screwdrivers include an LEDlight which allows users to accurately place the tip on the screw head in poorly lit work areas.