Best 18V Impact Driver Roundup
The impact driver has become one of the most popular cordless tools on the planet. Certainly, among professionals, it’s the number one tool for screw driving and other fastening applications. We rounded up the most popular models to see who can lay claim as the Best 18V Impact Driver currently on the market. The only requirements are that the impact driver has to be in the 18V/20V Max class and have a 1/4″ hex collet.
Editor’s Note: This shootout was originally published in December of 2015.
Unlike our Heavy Duty Cordless Drill Shootout, we opened this one up to everyone to get an idea of where each model performs compared to the others. In addition to the names you’re used to seeing like Ridgid, Milwaukee, Makita, and DeWalt, we also have a couple of value-minded options from Ryobi and Kobalt.
There’s also a twist – the Ridgid Stealth Force Pulse Driver technically belongs to a slightly different tool class called oil impact drivers. It uses hydraulics to deliver its force. While the basic action and design are the same, it is a different experience. However, Ridgid designed and priced this tool to be a replacement for traditional impact drivers, so it’s been invited to the party. In determining which is going to be the best 18V impact driver for you, we’re looking at performance, ergonomics, and value.
Numbers to Know
You’ll typically find three numbers that tell you about the performance of an impact driver. Like a drill, speed in RPM’s is how fast the impact driver is able to rotate with any load working against it. Torque is the amount of rotational force that the driver can transfer to the fastener – think of it as the muscle behind the bat speed. While we can nail down torque in drills pretty well, the action of an impact driver makes the torque rating much less accurate. Take it with a grain of salt until you see the driver in action.
Impact drivers add the metric of IPM, or impacts per minute. The highest torque occurs as the hammer impacts the anvil much like taking a hammer to your tire iron to break loose a stuck lug nut. Since this is where the highest torque occurs, it makes sense that the more times you can deliver it, the faster your driving will be. The combination of speed, torque, and impact rate result in a much faster driving experience than you can achieve with a drill.
Here’s a glance at those numbers for each impact driver. We’re not going to crown a champion based on published specs alone though.
*Note: The Ridgid Stealth Force torque and Gen5X impact ratings are not published at this time.
The vast majority of the time, impact drivers are either driving standard screws or lag screws, so we’ll be conducting our tests in that realm. There are times when we use them to tighten or loosen bolts when an exact amount of torque isn’t required, but that’s kind of tough to quantify. More manufacturers are coming out with impact rated accessories like drill bits and spade bits. We’re not quite ready to take those away from our drills, so we won’t be focusing on those… for now.
Try driving a screw with an impact driver and you’ll find that it’s pretty dang fast. If you’re not paying attention, you can sink your screw well beyond the surface of your material. In fact, many models can continue driving them until the bit tip loses contact with the screw head in softer woods like pine.
We’re turning to 3/4″ plywood as our test material. Each model is going to drive twenty-five 3″ drywall screws flush to the surface as quickly as it can. In order to minimize mistakes, each screw has a 1/4″ head start in the wood. This allows us to move quickly from one screw to the next and it’s deep enough to keep the screw from wandering or falling over at startup. If we have bit failures, camouts, or anything else unforeseen happen, we’ll stop the test and start it over from the beginning.
Medium Lag Screws
Getting into where the impact drivers start to earn their reputation over cordless drills, we’ll be driving 3/8″ x 3-1/2″ lag screws into stacked plywood. Thanks to wood’s tendency to split when driving such large diameter screws, we’ll be giving them the benefit of a 1/4″ pilot hole. Each impact driver is going to drive 10 lag screws flush to the surface consecutively.
Large Lag Screws
Finally, we’re going to test the muscle of each impact driver. Each participant is going to drive a 1/2″ x 6″ lag screw as close to flush to the plywood surface as it can. There will be no pilot hole this time – we just want to know who the strongest is. For the ones that can finish it off, we’ll also be keeping time as a tiebreaker. It will take 486 inch-pounds of constant torque to get the lag screw flush on the final turn – a number that may sound low, but is actually tough to sustain for this class of tool.