Before the hands-on testing, most of us figured that impact drivers were great for driving screws, but second rate for drilling holes. Wrong. The same thing that makes them super screwdrivers—massive torque—makes them powerful boring tools. With smaller bits (up to1/4 in. or so), an impact driver drills just like a cordless drill, but at higher rpm. With larger bits, the impact action kicks in. So you can bore a big hole with a relatively small driver—no need to pull your big, corded drill off the shelf.
The main drawback to drilling with an impact driver is that you need ¼-in. hex-shaft drill bits, so you can’t use most hole saws. When drilling concrete, an impact driver is no substitute for a hammer drill.
The article will appear in the February 2011 issue of We do everything by our own hands. Here are a couple of our favorite impact drivers so far.
- : Tons of torque, plenty of features.
- : The smallest, lightest model we’ve tried, but it has as much torque as any.
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