What is an Impact Driver

Understanding the Power and Versatility of an Impact Driver


Impact drivers are the best power tool when it comes to fastening and unfastening, impact drivers require less effort than what is required from a drill or electric screwdriver when fastening and unfastening.

Why are impact drivers so efficient at this task, below, we will look at how impact drivers work to help you better understand why they are better than drills or electric screwdrivers.

Impact drivers are different because they use what is known as rotational hammering function. The best way to explain it is using the following example:

Imagine you are trying to loosen the lug nuts on your car’s wheels. You are using a large wrench to try and twist the bolt off, but it has been screwed on so tightly that it will not budge.

It needs more torque to be taken off. The solution is to hit the end of the wrench with a hammer as hard as you can and as many times as you can until it loosens.

An impact driver does the same thing, if it encounters any resistance when trying to unscrew or even screw for that matter. It has an internal mechanism that hits the rotational part of the driver up to 50 times a second in some impact drivers. This helps it to produce enough torque to loosen or drive in any stubborn screws or bolts.

This tool does not rely purely on the spinning mechanism (RPM) to screw or unscrew, it has a hammering function, not to be mistaken with the hammering function on a hammer drill, which kicks in when things get tough.

This hammering function also greatly reduces the risk of stripping the screw head. When you only have high RPM at your disposal, the screwdriver bit starts to slip and eventually strip the screw head.

With the hammer function, also known as impacts per minute, you can reduce the RPM via the trigger and relay on the hammer function to fasten and unfasten screws without stripping the screw head.

High RPM only has the ability to spin fast without much torque behind it to loosen screws without stripping them

The internal hammering function in an impact driver is what makes it so efficient at fastening and unfastening, driving screws into wood and various other materials. This is the basics of how an impact driver works.

As you can see, the other popular fastening and unfastening power tools miss this hammering feature (hammer function in a drill is completely different to impact drivers), that is why an impact driver delivers better results for fastening and unfastening, regardless of if it is screws, bolts, nuts or driving screws directly into timber. If you currently do not have an impact driver and are planning to do a lot of fastening and unfastening, get one! As it will make the job so much easier.

What is an Impact Driver Used For?

The best use for an impact driver is used to fasten and unfasten screws, nuts and bolts. You can use an impact driver for the following tasks:

  • Screwing decking
  • Screwing together sheds
  • Fencing
  • Securing timber together
  • Loft boards
  • Screwing shelves
  • Building furniture
  • Screwing directly into brick with masonry screws
  • Driving long screws
  • Loosening stubborn screws, nuts and bolts
  • Fastening screws into thin sheet metal
  • Speeds up repetitive fastening and unfastening jobs

As you can see from the list above, there are many uses for an impact driver, and many more than mentioned in the list above, but it gives you the idea how useful an impact driver is not only for professional tradesmen, but home DIY projects as well.

How to Use an Impact Driver

Using an impact driver is relatively straightforward, but it does require some knowledge and caution to ensure safety. Here’s a basic step-by-step guide:

  1. Choose the Right Bit: An impact driver is versatile and can use a variety of bits. Choose the right bit for your task – whether it’s a Phillips, flathead, or a Hex bit.
  2. Insert the Bit: Once you’ve chosen the right bit, insert it into the chuck of the impact driver. Some models have a quick-release chuck that makes this process easier.
  3. Secure the Material: Make sure the material you’re working on is secure. You might need clamps or a vice to hold it in place.
  4. Position the Driver: Place the bit into the screw head or bolt. Hold the impact driver so it’s perpendicular to the material.
  5. Start Slowly: Start the driver slowly to create a groove in the screw head or bolt. This will help ensure the bit doesn’t slip out.
  6. Increase Speed: Once the bit is securely in the groove, you can increase the speed of the driver. The impact driver will deliver high torque to drive the screw or bolt into the material.
  7. Stop: Stop driving when the head of the screw or bolt is flush with the surface of the material. Be careful not to overdrive and strip the screw head or bolt.

Remember, an impact driver is a powerful tool. It’s best to practice on scrap material until you get the hang of it.

What’s the Difference Between an Impact Driver and a Cordless Drill?

The difference between an impact driver and a cordless drill lies primarily in their primary functions, power, and the specific tasks they are designed to perform.

An impact driver is a tool that’s primarily designed for fastening and unfastening screws as quickly and efficiently as possible. It’s much stronger than a drill in terms of the torque it can deliver. This extra power enables it to break loose stuck bolts and screws or drive them deeper into hard materials. An impact driver combines rotational force with powerful, short bursts of hammering force, which makes it particularly effective for its primary task.

On the other hand, a cordless drill is more versatile. Its main job is to drill precision holes. While it can also be used to fasten and unfasten screws, it doesn’t do so as efficiently or as quickly as an impact driver. The drill provides a constant torque and runs at a steady speed, making it suitable for jobs requiring control and precision.

Is an Impact Driver Similar to a Cordless Hammer Drill, as They Both Have Hammering Functions?

A common question with another type of drill is: Is an Impact Driver Similar to a Cordless Hammer Drill, as They Both Have Hammering Functions? While both impact drivers and hammer drills incorporate a ‘hammering’ function, the way they deliver that function and their primary uses are quite different.

An impact driver uses rotational and downward force to ‘impact’ the screw, providing greater torque than a hammer drill.

On the other hand, a hammer drill is designed primarily for drilling into hard materials like concrete, brick, or stone. It uses a rapid, hammering motion to pulverize the material while the drill bit rotates to remove the debris and create a hole.

While both tools have a ‘hammering’ function, the application of that function is very different. An impact driver is best for driving screws, while a hammer drill is best for drilling into hard materials.

So, if you’re working mainly with screws and need to do the job quickly and efficiently, an impact driver would be your go-to tool. For drilling precise holes and doing more versatile work, a cordless drill would be more suitable.

Can You Drill Holes With an Impact Driver?

Yes, you can drill holes with an impact driver, but it’s important to understand its limitations and the nature of the task at hand.

Impact drivers can be used for drilling small pilot holes into timber. They are powerful tools that can drive a drill bit into most types of wood with ease. However, due to their design, they may not be ideal for tasks that require precise or deep holes.

One reason is the chuck wobble: the design of an impact driver can cause the bit to wobble, which can lead to less accurate drilling. This might not be an issue for small pilot holes in wood, but for more precise tasks like drilling a hole into a wall for wall plugs. This lack of precision can cause problems such as making the diameter of the hole too big.

Another reason is the rotational hammering function of impact drivers. While this feature is great for driving screws, it can kick in when drilling, causing the bit to move slowly. This action can make it difficult to drill as you need it to spin at full power. This may prevent the drill bit from going deep enough into harder materials.

Therefore, while impact drivers can be used for drilling holes, they are not the best tool for all drilling tasks. For precision drilling, especially in hard materials, a dedicated drill is usually the better choice.

Is it Better to Use an Impact Driver or a Regular Screwdriver?

Impact driver vs screwdriver is a common question, and the choice between an impact driver and a regular screwdriver largely depends on the task at hand.

For small, simple tasks around the house, such as assembling furniture or tightening loose screws, a regular screwdriver should suffice. They’re easy to use, require no power source, and are generally less expensive.

On the other hand, if you’re working on a project that involves driving a large number of screws, especially into hard materials, an impact driver can be a game-changer. Impact drivers are more powerful than regular screwdrivers and can drive screws in more quickly and efficiently. They also reduce the strain on the user’s wrist, as they absorb the kickback that can occur when a screw gets stuck.

However, impact drivers are generally more expensive and require a power source, so they may not be the best choice for everyone. If you’re a professional contractor or frequently undertake large DIY projects, the investment in an impact driver could be worthwhile. But for occasional, light-duty work, a regular screwdriver should serve you well.

Is an Impact Driver Better Than a Cordless Screwdriver?

Yes, an impact driver is more powerful than a cordless screwdriver and hence better suited for heavy-duty tasks. Impact drivers deliver a higher level of torque and have a hammering action that can drive screws into tough materials more efficiently. This makes them ideal for construction projects or tasks that involve thick, dense materials.

However, for lighter tasks, such as assembling flat-pack furniture, a cordless screwdriver might be the better choice. Cordless screwdrivers are typically smaller, lighter, and easier to handle than impact drivers. They provide enough power for most household tasks without the risk of damaging the material or stripping the screw heads, which can happen if a powerful tool like an impact driver is used on delicate tasks.

So, while an impact driver may be “better” in terms of raw power, the right tool really depends on the specific task at hand. Both tools have their unique advantages and are best used in situations that play to these strengths.

Do You Need an Impact Driver?

I guess the final question on your mind is, do you really need an impact driver? It all comes down to the types of jobs you are doing, different tools for different jobs. If you’re putting together decking or putting together any other large structures that are mainly made of wood, then absolutely yes! Because you will be driving a lot of long screws, and you want to do it in the quickest time possible with the least amount of effort.

If you are also finding yourself needing to remove a lot of stubborn screws or bolts, then there is only one tool for the job, an impact driver. If you do a lot of drilling, and are thinking of replacing your cordless drill with an impact driver, then you absolutely do not need an impact driver and would be replacing it with the wrong tool.

However, a lot of us just like to have a selection of tools, in case we need them, and if you’re one of these people like me, then go ahead and get yourself one, below you will see reviews of some of the best impact drivers.