Hammer Drill vs Impact Driver – What’s the Difference?

  • February 7, 2019

Hammer Drill vs Impact Driver - Which is Best for Your Project

If you need more power than you can get from a hammer or drill alone for your next project, you may be considering getting a hammer drill or impact driver. Both of these tools provide extra oomph, and can speed up tough projects, and allow you to do so some tasks that you may not be able to do with weaker equipment.

However, if you’ve never used these tools before, you may not be sure which is right for your next project. We understand that struggle and want to make sure that you can pick the right one so that you don’t end up spending money on what will ultimately be a frustrating experience. Once you know the difference between these two tools, you should be able to find the tool that will make your jobs fast and easy.

Hammer drill pros

The hammer drill features an internal piston which hits the screw you’re repeatedly using while you’re drilling. That gives you some extra power while you’re working and may be the extra help you need to drive nails into a hard material. That makes them best for drilling holes through masonry, like concrete or drywall, and in some cases, bricks.

They tend to be more powerful than impact drivers, which can make a huge difference in how much time you spend working on a project. The hammer drill is also going to be the far better performer when drilling fresh holes. You can use them to drive screws, but the extra hammering action might break a weak bit or screw.

Hammer drills generally accept both round and hex bits, so you could use bits you already own in most circumstances. Many, but not all, hammer drills come with the option to turn the hammering action off, which allows them to work as a regular drill. A few models also have the option to turn the drill function off, allowing the device to function as a hammer. Models with that functionality tend to cost more, so it may be more economical to skip those extra features and use a hammer where you can.

hammer drill

A hammer drill

Hammer drill cons

Hammer drills tend to be more expensive than impact drivers. They have more power, and since they have a fundamentally different internal design than most drills, it’s not unreasonable that they often cost more. Of course, if price is your primary concern, the best hammer drills may be out of your reach.

They also tend to have an oversized clutch. This is going to be especially noticeable on portable hammer drills, especially if you’re used to using regular portable drills. The portable hammer drill will likely be larger than you expect.

They also have good grip on their bits, but they don’t use a locking collet, so it’s not as good as that which you’ll get on an impact driver. However, since the force is largely applied linearly, you shouldn’t expect to have problems with loose bits frequently.

There’s also a problem related to its vibrations. Some people have described using a hammer drill as holding a mini-jackhammer, and in our experience, that’s accurate. The rapid front-to-back motion that drives the bit produces a lot of vibration that can wear your hands out very quickly. Unfortunately, that’s a problem that comes with all hammer drills, though some take steps to reduce vibrations and how much you feel them.

Impact driver pros

Impact drivers are best thought of as better drills. They don’t have a hammering action like that of a hammer drill. Instead, they apply far more rotational power than a standard drill. Technically speaking, tiny internal parts are striking the turning mechanism hundreds or thousands of times a minute, providing consistent, powerful rotational power.

If you need to drive a long screw into studs or other hardwoods, or drywall, or softer walls, then the impact driver is the tool for you. Since they use a locking collet to hold the bit, you’ll never have to worry about it falling out or coming loose. They can also be used for loosening or tightening screws or bolts.

As long as you don’t need a specific torque like that which you would get with a torque wrench, you can use an impact driver. In fact, impact drivers are the younger siblings of the confusingly-named impact wrenches used by NASCAR pit crews and auto mechanics to take the lug nuts off tires.

If you’re dealing with a stuck nut or nail, the impact driver can deliver more force than you could without the use of a cheater bar, and with far more safety.

impact driver

An impact driver

Impact driver cons

Impact drives typically only accept hex bits that fit into their locking collet, so the range of bits you can use on an impact driver is smaller than with a hammer drill. While they have superior rotational power, they’re not great for drilling operations.

The extra rotational speed and power aren’t as useful when drilling. With a hammer drill, you get extra power in the direction that you want to drill. With an impact driver, you have to provide that extra power with your own muscle, which means it’s not much better than a standard drill in that regard.

That extra speed may not translate into faster drill times and could result in burning the edges of the drill site, which leads to a bad look if the area around the hole will be visible when the project is done.

You can also potentially apply too much torque to a bit with an impact driver and snap a thinner drill bit, which is something to keep an eye on if you’re trying to drill with an impact driver. In most situations where you’re not driving a fastener, but instead just trying to make a hole, the impact driver will be the wrong choice.

Should you use a hammer drill or impact driver?

If you need the most power you can get out of one of these tools, then you can’t go wrong with a hammer drill. However, if you’re getting a model for occasional home use, you might be better off with an impact driver, since you may not be pushing it to its limits with domestic jobs.

People who are going to be doing a lot of medium- to heavy-duty projects could make use of both tools since they’re useful in different situations. While you can use them somewhat interchangeably on light-duty projects, at the more extreme ends of torque and power, you’ll find that they rapidly diverge in terms of usefulness.

If your budget limits you to purchasing just one of these tools, it’s a good idea to get an impact driver. The impact driver can be thought of as a more versatile drill, and it specializes in the things that most people will be doing at home, which is driving in fasteners. However, if you really need to create holes, then you’ll be better off with a hammer drill.

We hope that our guide has helped you understand the differences between hammer drills and impact drivers, and has given you the information you need in order to maximize your next purchase.

More articles about impact drivers & hammer drills:

–> DeWalt DCD985 Hammer Drill/Drill Driver Review

–> Which hammer drill is our favorite for the money?

–> Which impact driver is our favorite for the money?

–> Are cordless models better than corded?

About the Author Adam Harris

Hi there! My name is Adam and I write for HealthyHandyman. I have a great passion for writing about everything related to tools, home improvement, and DIY. In my spare time, I'm either fishing, playing the guitar, or spending quality time with my beloved wife. You'll also often find me in my workshop working on some new project!