Hammer Drill vs Impact Driver: What Are The Differences?

If you’re just starting out with your work tool collection, or you’re looking to expand into cordless power tools, then you should be at least thinking of acquiring a hammer drill or an impact driver. However, you might be thinking: What’s the difference between a hammer drill and an impact driver?

What is a hammer drill used for?

Hammer drills are essentially regular drills, but with a hammering action option. In most hammer drills, there is usually a switch at the back of the drill to activate the hammering option. The effect is very much as if you’re holding a drill, and someone is hitting the back of the drill, for a jackhammer effect. This works particularly well with concrete and masonry. It’s particularly good for work when it comes to general house projects, but it doesn’t really have much of a use when it comes to projects that are more about woodwork.

What is an impact driver used for?

An impact driver also uses a hammering action, but in this case, it’s a perpendicular rotary hammering action. It’s as if you’re not only hammering the drill in, you’re also using an impact wrench action to turn the drill on the center axis. This creates more torque at specific moments, giving you more control. Also, it means that you’re not as likely to strip screw heads.

As can be expected, this works well for woodworking, where long screws may be used. However, the impact driver action can be unpredictable, be it a manual or an automatic function. It may not be a good idea when working on brass or other metals. Still, it works well on general woodworking projects and DIY or hobby works.

impact driver by dewalt
Inner mechanics of an impact driver

Do take note that for classic woodworking projects, there still wouldn’t be much use for an impact driver. However, when it comes to installations, cabinet installments, and any home or construction project that requires the fixing of equipment or other such to wooden supports, an impact driver is worth its weight in gold.

What are their basic differences?

It’s all in the direction of the hammering action as relating to the main shaft or axis of the drill. The hammer drill simply has a hammering action directly applied to the axis of the drill, and this creates in a pounding action. It’s great for working with rock or concrete. Once it pulverizes the target material, you can then drive the bit into it, to create an anchoring spot.

In the case of impact drivers, the force is also delivered at a right angle from the axis of the drill shaft, and is actually a rotating, hammering action. This is best used to drive in or loosen screws and bolts, normally from wood. They’re also used for loosening bolts from machinery. Impact drivers tend to be made for lighter duty than hammer drills, and they normally use hexagonal bits, while hammer drills use chucks and can be fitted with an extensive array of drill types for different materials. Finally, impact drivers can turn clockwise or counterclockwise, for tightening or loosening.

Proper Handling and Safety

When using any sort of power tool with drills or impact action, you should have the following:

1) Hardhat
2) Protective Goggles
3) Work Gloves
4) Safety Shoes
5) Thick clothes

When using either a hammer drill or an impact driver, it pays to be aware of how you are using the power tool. Make sure that you are drilling into the target area in as perpendicular an angle as possible. Otherwise, the impact action can easily shatter bits or send them flying, no matter how properly attached they were. Even if you have thick clothes and all the proper safety gear, a flying shard of metal is still dangerous shrapnel.

Like always, be careful while operating power tools of any kind!
Like always, be careful while operating power tools of any kind!

Most power tools for home use are now cordless. It’s a good idea to remove the battery while not in use, and to attach it only when you’re going into the work area. Also, test the power tool first before applying it to your target area. Finally, do make it a habit to put your manual settings back to the lowest after every use, this way, you can work your way up to speed safely.

Even if you’ve worked with hammer drills and impact drivers before, you should do a test run when you’ve just bought a new drill or driver. That way, you won’t end up being surprised or put in a dangerous situation. Do remember, these power tools can go through wood and concrete. Imagine what they can do to your body.

Do treat these power tools as if they are guns: point the active end away from any person.


The question you should ask yourself is: what are your planned projects for your house? On the other hand, if you’re using it for business, what projects are you contacted for?

Hammer drills
…are used with concrete, stonework, and masonry. If you’re going into projects that require you work with these materials, then you definitely will need a hammer drill – this is very important if you’re also doing work involving major support spars and foundational flooring.

Impact Drivers
…are more versatile, and in fact, some of them can pass for light-use impact drills. If you’re simply doing woodworking and installations that don’t border on heavy construction, then you’d be better off with an Impact driver for repairs, maintenance, hobby, or light construction/installation projects.

Additional Ressource: Compact Power for Drilling & Driving

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