IMPACT DRIVERS: Small Tool With a Big Difference

Building a deck, dock, picnic table or shed? An impact driver is a must-have tool for you. That’s because they’re the ultimate screw driving tool. Impact drivers sink screws faster than a cordless drill of the same size, and this matters because screws are a growing part of how things are built these days. But speed isn’t even the best thing about impact drivers. More importantly, these tools keep the tip of screw driving bits much more firmly engaged with deck screw heads, virtually eliminating the slippage and frustration that’s so common when driving screws with ordinary cordless drills. I’ve never seen anyone go back to using a drill for driving screws after they’ve tried an impact driver, and the reason boils down to the different ways these two tools spin.

The nose of every impact driver is made to accept the kind of standard, 1/4” hex-drive screwdriver bits available at hardware stores everywhere, but instead of non-stop rotation – as with drills – impact drivers rotate forward a half turn or so, then backwards a little, many times each second. The result is a rather loud, raspy sound when impact drivers are operating under load, but that’s a small price to pay for the benefits they offer. The two-steps-forward-one-step-back rotation pattern resets the screwdriver tip in the screw head, keeping parts engaged and eliminating slippage. This feature has always been the foundation of impact driver performance, and it is now being enhanced by a couple of things that surprise even a jaded old tool tester like me.

Better batteries and more efficient, brushless motors are the two most important innovations in the cordless tool world right now, and these virtues are poised to offer special benefits for impact drivers. That’s because the smaller and more powerful an impact driver is, the handier it is to use.

Manufacturers everywhere are scrambling to redesign cordless tools to include brushless motors, and that’s a good thing. Performance tests I’ve run show that brushless motors deliver much more work for a given battery charge than the kind of brush-style motors that have been around for decades. Brushless motors also last more than ten times longer than brush-style motors before wearing out. Watch my video tutorial of how brushless motor technology is built, and to see detailed results of my performance testing.

Third generation lithium-ion batteries are the second innovation you should know about. Not all brushless tools have these, but they’re worth looking for. First generation lithium-ion batteries became available for cordless power tools in 2005, and it was a huge advance at the time. What’s not so good is that some tool manufacturers are still using the original or second generation version of lithium-ion batteries today. Third-generation lithium-ion batteries deliver about 50% more run time and substantially more speed for a given battery size and tool, even though they don’t look very different externally.

For more than five years, the Makita BTD141 18-volt impact driver was my favourite. That’s an amazing length of time for any tool to stay on top of the heap. Milwaukee’s 2653-22 has just come out, and a couple of weeks of using it has convinced me that it’s now stolen the crown from the older Makita. The Milwaukee does a huge amount of work on a given charge, it’s fast, short and easy to handle. It’s also got internal circuitry to protect the motor and battery against overheating that prematurely shortens life in many other cordless tools.

The most common power tool question I get is simple to understand, yet not always simple to answer: “What’s the best brand of power tools out there?” The fair answer usually depends on the kind of tool you’re talking about, and the year you ask me. The surprising thing is that what often matters more than brand names are the executives currently behind a company at a given time. Tool users never see this side of things, but I do. It’s both fascinating and entirely predictable to see how specific corporate leaders breathe life and innovation into different power tool companies as they move from one brand to another within the industry. It’s a simple, numerical fact, for instance, that the greatest number of new cordless tool designs is coming from Milwaukee these days. This company is also being led by the same people who made strikingly big things happen in competing tool companies years ago. As with so many things in life, quality eventually comes down to people, not brand names.