Impact Driver vs Drill

There are countless types of power tool available to anyone from DIYers to professional contractors.

So, no matter what your needs are or your overall experience, you’re literally spoilt for choice.

Two of the most common types are the humble drill driver and the impact wrench – two tools which may look quite similar at face value, but that are intended for very different types of task.

Throw in variations on the two such as hammer drills, manual impact drivers, and impact wrenches, and things can quickly become confusing.

Fear not though, because regardless if you’re struggling to tell the difference between an impact driver vs drill driver, or you’re wondering which is the best choice for your tool arsenal or your next project, this is the guide for you.

Let’s get started…

An impact driver is a tool which uses a combination of rotational ‘impacts’ as well as a linear, rotational force to insert (or if the output is reversed, to remove) large fixings and fastenings.

They’re widely used by the likes of mechanics working on automotive projects, professional tradespeople handling construction work, and operatives dealing with product assemblies that require frequent tightening and loosening of nuts and bolts.

While they make look similar to conventional drill drivers, impact drivers provide considerably more twisting power, or torque (sometimes as much as two to three times more, in fact) even though they’re usually smaller and lighter.

They aren’t just stronger and more compact though; they’re usually quicker too, all thanks to the ability of most impact drivers to drive or remove fixings and fastenings at a much faster rate than standard drill drivers.

Speaking of speed, you can change an impact driver’s output speed by adjusting how hard you press its variable speed trigger, in a similar way to how you would with a drill driver.

Unlike a drill driver, however, impact drivers don’t come with a multi-speed transmission or a dedicated clutch, meaning it can be very easy to over-tighten fixings and fastenings with an impact driver if you aren’t careful with your trigger finger.

While it is technically possible to use an impact driver for drilling, it’s probably best to avoid this in favor of a drill driver if accuracy is required. The combination of the high torque and speed output on offer leads to vibration which means that precision drilling in a particular location to a set diameter, roundness, and orientation will be difficult.

Impact drivers typically come in a variety of different drive sizes (usually a 1/4″ hex drive), with a massive range of hex bits available that are tailor-made for working with different sizes and styles of fastening.

Most impact drivers on the market are cordless, often using 12-volt, 18-volt, and in some cases, 20-volt lithium-ion batteries, with the higher the battery voltage, the more powerful the impact driver usually is and the longer the available battery life.

There is also a wide range of corded electric impact drivers available too, should you prefer.

As mentioned, impact drivers rotate in the same way that drill drivers do, so clearly they’re intended for tightening and loosening various fixings and fastenings depending on the specific bit type used.

It’s their ability to deliver a sideways hammer action while rotating that makes them capable of providing a much higher torque output though, and this ultimately lets them handle tasks that ordinary drill drivers would struggle with, for example:

And as discussed briefly above, here’s what you shouldn’t use an impact driver for:

The inner workings of an impact driver are surprisingly simple as shown in the image below, with there being four main components:

• A motor
• A spring
• An internal hammer
• An anvil

As the impact driver’s motor experiences resistance from tightening or loosening a fixing, the spring-loaded internal hammer is pulled away from the anvil as the hammer continues to rotate.

At a certain point, the spring is released which pushes the internal hammer forward, and because of its profile and the simultaneous rotation produced by the motor, the hammer’s lugs impact with the anvil’s arms with sufficient energy to provide the impact driver with its renowned torquey output (and its significantly higher noise output versus a standard drill!).

The entire process then repeats for however long the user continues to press the trigger.

Here’s a video which shows the inner workings of an impact tool in detail, and slow motion:

Impact drivers are typically rated in impacts per minute (IPM), with, for example, the DEWALT DCF885 that we looked at previously producing a maximum of 3,200 IPM – that’s over 50 impacts per second!

As mentioned, many of the more popular impact driver models on the market are cordless electric tools that use lithium-ion batteries, with these differing significantly from the manual impact driver model shown below:

As alluded to by its name, a manual impact driver doesn’t feature a power source and is instead designed to be hit with a hammer to provide both rotational force and forward impact.

The forward impact aspect of the manual impact driver is worth reiterating as this is something that an electric impact driver doesn’t provide, and it makes the manual impact driver particularly useful when dealing with particularly problematic fixings, for example, those that are over-tightened or rusted in place.

Most manual impact driver models also come with a reverse function, meaning you can also use them to tighten screws to the point that would be unachievable with a regular screwdriver alone.

At the risk of confusing things further, there’s another type of tool to be aware of in this space, and that’s the impact wrench.

It’s worth viewing the impact wrench as the bigger, heavier, and stronger brother to the typical electric impact driver.

It’s like an impact driver on steroids, intended for only the most heavy-duty of tasks.

You see, whereas an electric impact driver like the DEWALT DCF885 delivers an impressive maximum torque of 117 ft-lbs, this is dwarfed by the DEWALT DCF894 impact wrench, for example, which is capable of a staggering 330 ft-lbs.

Because of this, the impact wrench is likely too powerful for the needs of homeowners, DIYers, and in most cases, even professional contractors.

The substantial torque on offer means that it’s best-suited to tightening and loosening sockets by the likes of mechanics doing automotive work (for example, those needing to fit or remove heavy lug nuts from a vehicle), and contractors working with only the largest nuts and bolts.

To handle the increased torque, impact wrenches often feature a 1/2″ square drive for attaching various sized sockets depending on the application, as opposed to the smaller 1/4″ hex drive typically found on impact drivers.

The two models also typically differ in terms of their power source, because while electric impact driver models are prevalent, many impact drivers use pneumatic power which can mean that you need to invest in a lot more equipment to get started, including an air compressor and air line.

It is still possible to purchase an electric impact wrench; however, the most powerful models are usually pneumatic-powered.

It shouldn’t come as a surprise that the drill driver topped Gizmodo’s list of the top-ten power tools that everyone should own.

Ask any DIYer or professional tradesperson which tool they rely on the most, and we bet that more times than not they’ll respond with their trusty drill driver.

You see, while their primary functions are to drill holes and drive screws, the list of tasks that these versatile tools can perform is virtually endless thanks to their expandable chucks (either keyed or keyless) which can hold hundreds of different hex or round bits for maximum flexibility.

Yes, they usually have much less torque than a typical impact driver which often limits them to lighter-duty tasks; however, in some ways, this can be viewed as a positive.

The lower torque and the slower rotational speed of the humble drill driver create much less vibration during use compared to with an impact driver, making them a far better choice for precision drilling requirements where a quality output is required.

They also differ in the fact that they typically feature multi-speed transmissions, which is different from the variable speed trigger often found on both types of tool which lets the user change the motor’s RPM, and subsequently the bit speed, based on how hard they press the trigger.

The DEWALT DCD777C2 that we looked at previously, for example, has two separate gears available – a faster one producing less torque for drilling holes, and a slower, more torquey option for when you need to insert or remove fixings and fastenings such as smaller screws or nuts and bolts.

Another significant difference and advantage of the drill driver vs impact driver is that the former comes with a clutch, whereas the latter does not.

Going back to the DEWALT DCD777C2 drill drive for a second, it has fifteen clutch settings available that are selectable by twisting a handy torque adjustment collar as shown below:

Each of the various clutch settings matches a specific torque setting, ensuring that the drill driver stops driving once it reaches the corresponding torque level to stop the head of the fixing stripping usually due to cam-out, being torn off completely, and to prevent you from inserting the fixing too far – all of which are common issues that can easily occur with an impact driver.

Many drill drivers also come with a hammer function to improve performance while drilling into masonry, although, the way this operates is quite a bit different to how an impact driver operates as discussed here.

Lower-powered drill drivers are well-suited to lighter duty tasks such as assembling furniture and household DIY, while more powerful models (for example, those with a larger capacity battery, a more powerful brushless motor, and higher no-load speed) will be better suited to handling the drilling and driving needs of professional users.

Examples of general tasks that a drill driver is capable of performing include:

And because of the lower torque on offer versus an impact wrench, here are some of the tasks that you should probably avoid tackling with a drill driver in most cases:

There are two main types of electric motor on drill drivers, either brushed or brushless.

In simplistic terms, a brushed motor features carbon brushes which electrical charge from the battery travels through as the brushes drag against the motor’s spinning commutator, whereas in a brushless both the carbon brushes and commutator are removed in favor magnets.

By removing the need for two components to drag against each other, brushless motors generate much less friction overall, causing the motor to run much cooler during use, with a higher level of efficiency and better overall performance versus a brushed drill driver.

Brushless motors also typically require less long-term maintenance versus brushed motors, as the carbon brushes in the latter are prone to wearing out and needing replacing as a result.

There is a price to be paid for all this extra durability, better performance, longer battery life, and reduced maintenance, however, as drill drivers featuring brushless motors tend to be considerably more expensive than those with standard brushed options.

Is the extra price of a brushless motor justified in our opinion? Yes, if you’re going to be regularly using your drill driver regularly, but if you’re only going to be tackling the odd bit of DIY every few weeks or so – probably not.

A hammer drill, often referred to as an impact drill, percussion drill or rotary hammer drill, shouldn’t be confused with the impact driver tool that we discussed above.

The primary function of a dedicated hammer drill (or the hammer function) is to drill through more robust materials such as masonry (for example, concrete) or metal that the standard drill setting on a drill driver would struggle with.

There are two main options available as shown below:

1. A dedicated hammer drill which features a hammer function only.

2. A drill driver which has an optional hammer drill setting.

You should never use a dedicated hammer drill or the hammer setting on a conventional drill driver to drive screws or to tighten nuts and bolts, regardless of their size.

It’s common to see both corded hammer drills, and increasingly, cordless models as lithium-ion battery technology continues to improve.

As mentioned above, a dedicated hammer drill (or a drill driver’s hammer setting) is the best option for when you need to drill into more robust materials.

Examples include:

The main reason why a hammer drill works so well when drilling into more robust materials like masonry is because of its hammer action which punches the drill bit in and out as it rotates to provide greater direct force into whatever you’re drilling.

Neither the hammering action or the extent to which the drill bit gets pushed in and out is particularly significant, but this process happens several thousand times per minute which makes it incredibly effective overall as it continually chisels away at whatever material you are drilling.

The mechanism which causes the hammering action is different depending on which type of hammer drill you are using.

On a conventional drill with the hammer setting activated, two ribbed discs rotate past each other, clicking in and out as they go to create the hammer action. The user needs to maintain pressure on the drill bit and chuck for this to function, as without it the clutch disengages the discs to prevent unnecessary wear to the drill’s components.

Rotary hammer drills, on the other hand, often feature a cylinder of air which gets compressed by a piston to drive the bit forwards as the user drills.

The main difference between a hammer drill vs impact driver is that the former is intended for drilling into tougher materials, whereas the latter is designed to tighten and remove fixings and fastenings.

Conversely, an impact driver shouldn’t really be used for drilling, and a hammer drill shouldn’t be used for driving screws or working with fastenings.

The next difference comes from how they exert additional force to help them the tasks they’re intended for.

A hammer drill, for example, mixes lateral force (the driving motion in and out of the drill bit) while it rotates to help it effectively pound through whatever you’re drilling.

An impact driver, on the other hand, adds rotational impacts to the standard rotating motion to provide the extra torque needed to tighten bigger fixings and fastenings.

Unlike conventional drill drivers, dedicated rotary hammer drills are similar to impact wrenches in that they don’t usually feature a variable clutch, although, many do feature a variable speed trigger to let you adjust the output speed to best-suit whichever task you’re completing.

TL;DR? (too-long, didn’t read)

Skipped immediately to the end?

No problem.

Here’s a table showing some of the key information that we’ve provided above for both types of tool.

We’re aware that there will be some special exceptions to the information below, so this is probably best viewed as a general categorization only!

Scroll table if needed

The Bottom Line

There’s a reason why companies like DEWALT, Makita, and Milwaukee offer combo packs that include both an impact driver and a drill driver.

And there’s a reason why these packs are so popular.

You see, despite their similarities, an impact driver and a drill driver are two very different types of tool, and so it isn’t usually a case of going for one or the other.

Take a decking project, for example, where you’d struggle to drill accurate pilot holes with an impact driver, and where you’d find it equally challenging to drive larger bolts and fixings with a conventional drill driver.

We know that this may sound like an extreme example, but the truth is, we regularly find ourselves tackling projects that require us to swap between the two tools in a bid to take advantage of the strengths of each and to achieve the best possible finish.

We’d genuinely be lost without both.

But, is owning an impact driver and a drill driver a viable option for you?

Only you can determine this based on a few factors – for example, your aspirations in terms of the types of project you want to tackle, the quality of finish you aspire to, and perhaps, most importantly, your budget.

Regardless of your choice though, at least you now know have a better understanding of each type of tool, and what you can reasonably expect to achieve with one, the other, or both.

Good luck!