If you use power tools frequently around your home, you have probably run into this question before: What is the difference between a hammer drill and an impact driver? These two tools look similar, are operated in a similar way, and may, at first glance, seem to do similar things. But the truth is that these two tools each have a unique purpose – and there are other things different about them as well. From the way you operate them, to how much they cost, a hammer drill and an impact driver are different. Let’s take a close look at what each of these do, and when you should choose one over the other.
Table of Contents
- 1 A Quick Comparison of Hammer Drills and Impact Drivers
- 2 The Hammer Drill: What Is It, and Do You Need It?
- 3 The Impact Driver: What Is It, and Do You Need It?
- 4 Here’s a good way to understand how an impact driver works:
- 5 Impact Driver vs. Hammer Drill: Do You Need One or the Other?
- 6 Check Out the Multi-Use Tools
- 7 The Bottom Line
A Quick Comparison of Hammer Drills and Impact Drivers
Below, we’ll cover each of these tools in depth so that you understand exactly when you may need one or the other. But let’s do a quick comparison so you understand the big differences right away.
If you strip away all the things that make these two tools different for usage, and just consider the way they operate, you’ll see the major difference between a hammer drill and impact driver. A hammer drill operates in a back and forward motion – like a hammer. An impact driver operates in a rotary manner – like a screwdriver. And while many models of either type of tool allow you to use them as a standard power drill, this is really the bottom line. A hammer drill is a powered hammer, primarily made to drill holes through concrete and drywall, and an impact driver is a powered screwdriver, primarily made to drive screws into concrete and drywall.
Once you understand that major difference, you can start to see when you may need one or the other. However, there are quite a few other specifics that make these tools different, so don’t decide just yet. Now let’s take a close look at these two tools.
The Hammer Drill: What Is It, and Do You Need It?
What is a hammer drill? Well, have you ever tried to use a drill to create a hole in drywall before you inserted a plastic anchor? What if you needed to do something similar in a concrete wall? A hammer drill is the tool you’d use.
To understand exactly how a hammer drill works, let’s talk about the parts of a drill. A standard power drill is made up of around six important parts:
- The grip is where you hold the drill. A hammer drill has this part as well.
- The trigger is what you pull or press back with your finger to work the drill. A hammer drill is operated in the same way.
- There is usually a switch that reverses the direction of the drill bit, so that it turns either clockwise or counter-clockwise.
- There is a torque selection ring on the end of the nozzle, where you can choose how much torque you want the drill to use for a job.
- Connected to that ring is the chuck, the part that holds the drill bit.
- Finally, there is a drill bit, which is a long metal tool, inserted into the chuck, which cuts a hole into the surface you use it on. These can come in many shapes and sizes, but they are all designed to be rotated into the material in order to cut a hole in the material.
So, a hammer drill contains many of these parts, but it doesn’t work in the same way. Where a standard power drill is designed to rotate the drill bit into a material, a hammer drill is designed to pound into the material. Instead of choosing the torque with the selection ring, and seeing the drill bit, held by the chuck, rotate, you’ll be holding what amounts to a mini jack hammer. The hammer drill doesn’t have a solid nozzle leading to the chuck.
Instead, it has a motor, connected to what is called the housing. Inside the housing, the motor vibrates another part of the hammer drill in a back and forth motion, so that it pounds into the material. This part that is moved is called the bit or drill, and it works similarly to the way a drill bit does. It is also held in place by a part called a chuck. Instead of having grooves to help it cut into the material while being rotated, this bit features a blunt shape that is meant for pounding holes into a surface.
Where the chuck connects to the housing, where the torque selection ring would be on a standard drill, there is usually a second handle to help the user keep the hammer drill controlled. The back and forth motion can cause this tool to be a little harder to handle.
Some hammer drills are actually two-in-one tools that can be used as standard rotating drills as well. These tools will have a special setting for the hammer drill function that can be turned off.
Using a hammer drill isn’t necessarily easy, but it’s also not rocket science. You’ll need to set the depth for the drill bit. This means that you need to know how deep you want the hole to go, and use the depth stop tool attached to the hammer drill to help guide you.
Next, you need to be sure you are holding the hammer drill properly. It must be property balanced to keep your hole precise; otherwise, you’ll end up with a very big hole that you didn’t mean to make. Stand firmly and grip the hammer drill with both handles. Lean into the drilling as you use it and use your front hand to keep it steady and balanced.
Now, start slowly and make sure that you get the hole precisely where you want it. It’s a good idea to start extremely slowly and create the beginnings of the hole first, and then allow that initial beginning to keep the drill bit in place while you continue at full speed.
You don’t want to lean into the drilling with all of your strength, because the drill bit is already under pressure. It may break. Just use enough of your weight to keep the hammer drill steady. If you start to build up a lot of concrete dust, you can withdraw the drill just a little to remove some of it. If your drill is of good quality, and the bit isn’t worn out, you should be able to drill a two-inch-deep hole in concrete or bricks in less than 60 seconds.
You would choose a hammer drill if you wanted to:
- Make a hole in stone
- Make a hole in concrete
- Make a hole in bricks
- Make a hole in mortar
- Or drive an anchor into any of these materials
A hammer drill should not be used with screws, ever. Let’s take a look at the tool for screws.
The Impact Driver: What Is It, and Do You Need It?
The one important thing that a hammer drill cannot do, is rotate. It pounds back and forth; but some things, such as screws, need to be rotated into a surface in order to anchor them in place. However, you may be thinking that you can do that with a basic drill, right? Well, not always.
Think of an impact driver as a much more powerful and precise standard drill. It offers more rotational torque than the standard drill, and also combines this with an extra boost of power with every twist. This means that it can drive screws into masonry, or surfaces where a standard drill just isn’t cutting it. It also means you can perform tasks faster than a standard drill might.
The parts of an impact driver include the grip, forward/reverse switch, trigger, and motor, similar to a hammer drill. But there are two parts of an impact driver that are just a little different.
First, most impact drivers include an LED light under the bit, to allow you to see the detail of your work. Second, the chuck on this tool doesn’t accept a variety of bits made for different jobs. The impact driver uses a hexagonal shank to cut into the surface that you are drilling.
Here’s a good way to understand how an impact driver works:
Picture turning something with a wrench. Every time you turn the wrench, you add a little bit of power to the wrench by striking it with a hammer in the direction that it is turning. Most people could hit the wrench about once a second if they were fast and accurate. An impact driver adds a boost of power to every turn of the bit 50 times per second. That amount of power is what allows the impact driver to cut through concrete, stone, and other tough materials.
There are a couple of downsides to this more specific tool. It doesn’t have a clutch, and it also doesn’t accept round shank drill bits. There are standard drills that are combination tools that can be turned into impact drivers, which may be a good choice for a carpenter or handyman that frequently needs to work with brick, stone, concrete, or other hard surfaces.
Using an impact driver is similar to using a standard drill. First, choose which bit you want to use, and then determine if you want to put the bit in a bit holder for some extra length. Then insert into the chuck and set the impact driver to forward. Turn on the light, set the bit where you want it, and carefully pull the trigger until the bit begins to turn. Keep in mind that this can be a noisy tool.
While you are working, you can start to increase the speed once you know for sure you are steady. Some impact drivers have a speed setting near the bottom of the grip, be sure to check this before you get started.
While it can seem like an impact driver is only for very specific cases that a standard drill can’t cover, they can be very useful tools. You may consider one if you have to do any of these things:
- Remove bolts from metal structures.
- Install giant screws in solid lumber, metal, concrete, and other hard surfaces.
- Drive smaller, hidden fasteners with extreme precision.
Here’s one very important reason to have an impact driver. Do you do any sort of handyman or DIY work, and have arthritis or wrist problems? The torque control of an impact driver ensures that you never have to worry about the driver seizing and turning in your hand. This can protect your hands and wrists from painful wrenching and injury. This may also be a good option for professionals who want to limit job-site injuries for employees.
Impact drivers don’t take the place of a standard drill in every situation. You don’t always need that much power, and you could damage a more delicate material if you use the impact driver too hard. But it is an excellent tool to have if you work with anything tougher than drywall.
Impact Driver vs. Hammer Drill: Do You Need One or the Other?
If you are trying to decide between a hammer drill and an impact driver, the question really isn’t which is best for the job. Just by knowing what each does, that much will be obvious, since they both do different things. If you need it to do one specific type of job, get the one that does what you need. You can also consider renting this tool if you just have a single job to do, because they can be pricey.
However, if you are more interested in rounding out your tool kit with a highly useful and versatile tool that can help you in many situations in the future, that can be a harder decision to make. Start by asking yourself what types of jobs you do more of. Do you need to drive screws into solid materials, or punch holes into solid materials, more often? Consider making a list of all the types of jobs you do on a normal basis and see how many would be best suited by a hammer drill, and how many are better suited by an impact driver.
Finally, consider that these two tools are very complimentary, and you couldn’t go wrong by having one of each. If you are a handyman or DIY lover of any sort, you’ll find that both of these tools can be very useful to your tool box.
Check Out the Multi-Use Tools
Finally, it’s also a good idea to check out standard drills that can also be hammer drills or impact drivers. Be sure to keep in mind quality when it comes to these tools. The more a tool tries to do, the more likely it is that quality is sacrificed in certain areas. These all-in-one tools will be more expensive, but they can also save you a lot of space and time.
Consider a cordless option no matter which tool you use. This allows you to take the tool wherever you need it to go, no matter what.
The Bottom Line
The bottom line is that these two tools each do something different but important in the world of construction and DIY projects. Both are great assets to any toolbox, but you may not need both, or even either, depending on what you work with. Look around at your most common projects and you’ll see quickly which of these tools is best for you.