What Is an Impact Driver and When Should You Use It?

“What is an impact driver?” is a worthy question from many people using power tools such as a drill driver, an impact wrench,  and the impact driver itself. Perhaps due to their closely related applications.

Power drivers are essential tools in any workshop today, replacing handheld screwdrivers. They make the insertion and removal of screws easy and fun regardless of the simplicity or complexity of the object at hand.

Apart from woodworking, power drivers are also helpful in making threaded holes in non-ferrous metals, concrete, drywall, plastic, and steel. In addition, they drive in a variety of fasteners, such as wood screws, concrete screws, and drywall screws.

Away from the many power drivers available today, this article focuses on the following aspects.

  • What is an impact driver?
  • When to use an impact driver
  • Do you need an impact driver?
  • Impact driver buying guide
  • Impact driver safety tips

What is an Impact Driver?

An impact driver is a powerful tool used for driving in long screws or bolts more efficiently on tough surfaces that, otherwise, drill drivers may not. They are lightweight handheld tools that can be corded or cordless.


To an untrained eye, an impact driver closely resembles a drill driver. However, they are two different tools right from the bit loading process. To load and unload a bit from an impact driver, you pull its collet forward. The collet uses ¼ -inch hex bits.

Impact drivers have a higher torque that uses concussive force to drive screws two to three times faster and more efficiently than a typical drill driver. As a result, you’re less likely to strip the screws or twist your wrist.

In addition, an impact wrench drives in screws with more precision.

When To Use an Impact Driver

Impact drivers are versatile tools that anyone looking to upgrade their toolkit should include in their power tool arsenal. Apart from driving in long screws and bolts into a hardwood where a driver will stall, an impact driver also doubles as a drill.

To use the tool, press the trigger button position near your index finger when holding it appropriately.  You can set it to the desired speed using the variable speed controls.

In addition, there are clockwise and anti-clockwise settings depending on whether you’re driving in a bolt or unscrewing.

An impact driver is an excellent fastening tool for screwing down plywoods, building decks, and installing tile backer boards. It causes less stress to your wrist and arms, thanks to its extra power. However, the tool does not have a multi-speed operation or adjustable clutch.

One major setback about impact drivers, though, is their noisy operation. As a result, you may need hearing protection such as earmuffs for those who are sensitive to noise. Otherwise, the noise is not a concern when used over a short duration.


An impact driver’s collet fits various hex-shaped driver bits. For instance, there is a set of up to 70 bits you can use. The tool is light and compact but more potent than comparative power tools such as a drill driver. Bits operate in a one-step back-two-step-forward.

Impact drivers also use different motor voltages, usually between 12-volt to 20-volt. The battery sizes are generally 12, 18, and 20. The larger the motor voltage, the more heavy-duty applications it will handle.

Note that there’s no significant difference between an 18-volt battery and a 20-volt.

Impact drivers deliver up to 50 bumps per second, making them more efficient for driving in or unscrewing thoroughly wedged-in screws and bolts with less effort. Thanks to their internal hammering mechanism.

How an Impact Driver Works

Inside an impact driver, there is an anvil, hammer, and spring. When the driver encounters resistance, the spring pulls the hammer back and winds itself tightly.

The hammer then clears the lag on the anvil and plunges forward to unleash the power stored in the spring, striking the anvil. Such an impact-high torque allows the impact drivers to drive screws into tough materials more efficiently.

Do You Need an Impact Driver?

If most of your projects are drilling holes and occasional driving of medium-sized screws, the drill driver will suffice.

However, for more intricate and demanding tasks such as plywood subfloor installation and deck building, an impact driver will cut the time spent using a drill driver by more than a half.

Besides the satisfaction they offer, impact drivers are also very light, making them suitable for working on long projects.

You may need to determine the best impact driver to use in each project. For instance, cordless impact drivers are the most common and suited for outdoor projects away from a power source.

What to Consider Before Buying an Impact Driver

Before settling for an impact driver, you’ll need to determine the nature of your projects, such as whether you’ll be drilling wood or concrete and if you’ll be using small screws on softwood or large screws on hard surfaces.

Here are more tips when buying an impact driver.

Corded or Cordless Impact Driver

If most of your projects are outdoor, a cordless impact driver is your best companion.

You may need to go for a battery with high voltage to take you longer before replacement. Just keep an extra battery to replace when one drains out.

However, although impact drivers are generally lighter, the high voltage will translate to larger and heavier batteries, which may also be difficult to slip out of the tool belt.

Corded or Cordless Impact Driver

Power vs Control

Consider a combi drill or a standard impact driver if your projects use softwood or other soft materials like plasterboard. Such moderate impact drivers are less likely to damage the material when your screws strip.

Note that impact drivers have variable speeds but will still exert a higher torque when running at low speeds. The speed depends on how hard you press the trigger.

You may consider some impact drivers with speed selector switches to regulate the torque, depending on the nature of the application.

Brushed vs Brushless Motor

Impact drivers with brushless motors have longer battery life between charges, generate less heat, and are more powerful and efficient. However, they are also more expensive than brushed motors.

Voltage vs Torque

Most corded power tools are built to offer a higher torque for more intense screw driving.

However, as impact drivers continue to take centre stage as the future of screw driving, cordless impact drivers are built with more motor power to offer almost the same rotational power as their corded counterparts.

Impact drivers with high-voltage batteries can now deliver almost the same power while also managing longer hours and driving larger fasteners.

Safety Tips

Screw or bolt stripping is a common occurrence before getting used to impact drivers. In addition, the loud noise when running can also pose some risks to the user.

Below are tips on staying safe when working with an impact driver.

  • Read manufacturer’s instructions: Impact drivers come with different features that may require specific operating instructions. Go through the instructions to learn the safest way to manage the tool, including handling the battery safely.
  • Use the right accessories: One significant advantage of an impact driver is the seamless replacement of sockets and other accessories such as battery and hex bits.

Use compatible accessories for specific applications to avoid damages to the tool and the workpiece. Note that the screws or bolts will easily strip off when you exert a lot of energy on the screw, which occurs mostly if the socket is loose or too large.

  • Be aware of your work area: Use signboards to keep people away from the workplace. No one should stand behind you while operating an impact driver. That way, everyone stays safe from the possible stripping of screws and bolts.


  • Proper lighting: Work in areas with adequate lighting systems or access to sunlight.
  • Wear protective gear: Stay safe with the proper protective equipment when using power tools. Ensure you have gloves, protective glasses, earmuffs, and a face mask. You may not need earmuffs for projects lasting a few minutes.
  • Use the tool appropriately: Grip the device correctly, ensuring it is steady and firm in your hands. Your index finger should always press away from the trigger button.

Unplug your corded impact driver when not in use. For corded impact drivers, take out the battery before storage; that way, you prevent the tool from starting in case of an accidental impact.

Avoid using corded impact drivers in damp conditions to avoid possible electric shocks. Use a firm footing when working in raised stations. No one should be directly below.

Bottom Line

Now that we’ve answered, “what is an impact driver?”, it’s time to invest in one that will work efficiently for your unique applications. Applications that may require an impact driver include:

  • Installing a plywood subfloor
  • Building a deck
  • Screwing a treehouse together
  • Applications involving a lot of long wood screws and bolts

Before buying an impact driver, look at the ergonomics, driver voltage, chuck size, corded or cordless, and power versus control.

Screws are prone to stripping, especially for new users so, ensure you wear protective glasses and earmuffs to protect you against loud noise. Remember to keep your workplace free from clutter.


Appliance Reviewer