Hammer Drill vs Impact Driver Hands-on Testing
Your Hammer Drill and Impact Driver may be Capable of More than you Realize
For this Thursday Throwdown, we’re looking at things a little differently. Using Metabo HPT’s MultiVolt hammer drill and MultiVolt Triple Hammer impact driver, we’re going to see how effectively you can do all of your drilling and driving with just one tool or the other. In our hammer drill vs impact driver competition, we’ll look at driving speeds, drilling speeds, and the attributes of each tool.
Hammer Drill vs Impact Driver Design Differences
Before we jump into our competition, let’s take a quick look at the basic design elements of these two popular tools. Both tools use rotation to drill or drive, but the ways they accomplish it are very different.
The main differences are in the type of torque and type of impact you get from each.
Hammer drills (and standard drill drivers) have sustained torque that’s constantly working to spin your bit. When you switch into hammer drill mode, you engage a mechanism that hammers in and out from the chuck. The speeds can reach well over 30,000 blows per minute.
Heavy-duty hammer drills like the one we’re using for this article have a chuck that adjusts to fit bits up to 1/2″ in diameter.
The impact driver has a lower level of sustained torque. When it reaches its peak, its hammer slips over an anvil and then slams into the opposite anvil, driving the motion using a momentary amount of torque that’s typically higher than a hammer drill. The hammer and anvil design impacts rotationally at a rate that can push over 4,000 impacts per minute (IPM)
Standard impact drivers can only accept 1/4″ hex shank bits.
For a more thorough explanation, check out this article:
Hammer Drill vs Impact Driver Testing
We tested the Metabo HPT (Hitachi) hammer drill vs impact driver in a battery of tests. We factored in and tested everything from speed to power to ergonomics. After hours of testing, we drew some pretty firm conclusions.
Driving Speed: 1/4″ Ledger Screws
When you look at the no-load speeds of hammer drills and impact drivers, the impact is much faster. It’s very common to see speeds 3,000 RPM or higher whereas hammer drills are typically 2,000-ish. With a light load, such as drywall screws, the impact driver is usually faster.
But what happens when you put a bigger load on it? Using 1/4″ ledger screws, our hammer drill was faster by a significant margin. It took less than a second to fully drive each one. On the other hand, the impact driver averaged about 3 seconds.
Verdict: Hammer Drill
Drilling Speed: 1/2″ Twist Bit
With a 1/2″ Milwaukee Red Helix titanium twist bit, our impact driver didn’t need to do a ton of impacting and it was able to keep its RPMs high. That gave it about a 1.5-second advantage drilling through 5 sheets of stacked OSB.
Verdict: Impact Driver
Drilling Speed: 1″ Spade Bit
Moving to a 1″ Bosch Daredevil spade bit meant both tools had a lot more material to remove. Here, the hammer drill’s sustained torque took over, giving it an average lead just under 4 seconds.
Verdict: Hammer Drill
Drilling Speed: 1/4″ Concrete Bit
Switching to a 1/4″ Bosch Daredevil Multipurpose bit and a section of concrete, we got a surprise result. The hammer drill’s chipping action should have given it higher drilling speeds in concrete, but these two tools were almost identical in their average speeds.
You can make the argument that the hammer drill would begin to build a lead with larger bits, and there’s something to be said for that. However, we recommend moving to a rotary hammer at that point if you have access to one.
Hole Saws, Self-Feed Bits, and Auger Bits
Where the hammer drill wins it for drilling is with some of the other types of bits. Hole saws, self-feed bits, auger bits, and others don’t come with a 1/4″ hex shank. For that matter, not every twist bit, spade bit, or concrete bit does, either.
That means you can’t use a full range of drill bits in an impact driver and you need a hammer drill or drill driver for at least some of your work.
Verdict: Hammer Drill
Impact Driver vs Hammer Drill Noise Levels
There’s no getting around the fact that impact tools are louder than drills. Indoors, we measured our impact driver right at 100 decibels while the drill was just 88. 12 decibels is a huge difference: more than twice as loud and 16 times the sound pressure level. If you want the benefits of an impact driver without as much sound, consider a hydraulic impact driver.
Hammer Drill vs Impact Driver Size and Weight
If you don’t mind wearing some hearing protection, your impact driver is usually smaller and lighter than your hammer drill. When we’re talking about heavy-duty hammer drills, it’s a massive difference you can easily see and feel.
That changes as you shift to compact hammer drills, though. The impact driver is usually still more compact by quite a bit, but the gap between the weights shrinks. Your impact driver is typically the lighter of the two, though.
That can change when you’re looking at value brands. Some popular Prosumer brands, like Ryobi, have bulkier impact drivers and the size/weight difference is much closer.
Verdict: Impact Driver
I’m not going to go over every little feature between the two tools. However, there are some key differences that really make a difference in what it’s like to use them.
An impact driver’s 1/4″ hex collet only accepts 1/4″ hex shank bits. However, it’s incredibly easy and quick to change them out. Some offer one-hand bit insertion and a spring ejection.
Hammer drills have a 1/2″ ratcheting chuck (3/8″ on smaller models) and accept a wide range of bit diameters. It takes much longer to install or remove them, though. Fortunately, most handheld models are now keyless chucks, simplifying the process compared to your grandfather’s drill.
Both tools can have manual or electronic speed control switches. Electronic controls are more prevalent in models that have brushless motors and a few models also offer smart custom controls.
Impact drivers can be 1 speed on more budget-friendly models, with 2-speed and 3-speed models being more common on the Pro end. Some models integrate preset assist modes that can help with driving self-tapping screws, offer a controlled start, auto-stop in reverse, and/or more.
All but the most basic drills have 2 speeds with a few models offering 3 or 4. To switch modes between driving, drilling, and hammer drilling, you typically twist the collar to the mode you want to be in. Some put the drill’s clutch on the same collar while others separate them.
Some hammer drills include a clutch system that senses when your bit binds and automatically shuts the motor down much faster than you can react and let go of the trigger. It helps prevent injuries and is a feature we highly recommend on your heavy-duty drill. It’s also a feature that’s available on the Metabo HPT MultiVolt hammer drill we tested.
Impact drivers and impact wrenches don’t need one. Even when the rotation comes to a complete stop, the hammer keeps hitting the anvil and slipping back over. Even though an impact driver’s impacts transfer vibration to your hands, it makes metal fastening much easier to deal with than a drill. It’s one reason that you might choose an impact driver for larger fasteners like our ledger screws even though a drill might be faster.
Many hammer drills and impact drivers have a similar light placement just above the battery or just below the chuck. The impact driver’s collet makes it much easier to place 2 or 3 LEDs around the chuck, nearly eliminating shadows from every direction. A few drills also pull it off, but it’s much less common.
Most of the time, every hammer drill has an impact driver that pairs with it and you can find it in a combo kit with a couple of batteries to get the best overall value. They’ll also be available individually as a bare tool and/or with a battery or two.
The pricing structure is pretty close for the individual tools. The impact driver is often within $10 or so of the matching drill driver and it might be another $10 or $20 to add the hammer function.
In the case of our two contestants, here’s what you’re looking at:
Metabo HPT MultiVolt Impact Driver
Metabo HPT MultiVolt Hammer Drill
The Bottom Line
The big takeaway for us is that drills have the capability of fastening more quickly than impact drivers in the right applications and impact drivers are far more capable at drilling than you might think.
We still prefer having both tools, with the majority of fastening be done by an impact driver and the majority of drilling going to the hammer drill. If you absolutely have to pick just one, grab a hammer drill for its wider range of accessory compatibility.
Our conclusions are somewhat relative, though. If we used a compact hammer drill instead of a heavy-duty model, some of the results would change. It’s something to keep in mind if you’re looking for a hammer drill that’s on the lighter side.