Choose the Best Cordless Drill or Driver

Image Gallery STEVE MAXWELL

Today almost all drills are cordless, and most do a terrific job driving screws and boring holes in wood, metal or masonry. There are three main types on the market: ordinary drills, drill drivers and impact drivers.

Ordinary drills. Every drill of this sort has an adjustable “chuck” that grips drill and driver bits of various sizes. Better models spin both clockwise and counterclockwise at varying speeds, depending on how far you pull the trigger. Drills are often categorized by the maximum diameter of bit they can grip in the chuck. You’ll find three-eighths inch is ideal for a general-purpose tool; a half-inch chuck is better for heavy-duty use.

Drill drivers. As handy as an ordinary drill may be, a better choice for all-around use is a drill driver. It has the same features as an ordinary drill, but with one addition that makes screw driving more efficient: an adjustable torque clutch. This popular feature regulates the twisting power, called torque, that's applied to a screw, which simplifies jobs like driving multiple screws to the same depth.

Impact drivers. If you already own a regular drill but sometimes have trouble with driver tips slipping out of screw heads, spinning around and damaging the screw and the driver tip, you might want to consider an impact driver. You can't drill holes with an impact driver, but it drives screws much better than a standard drill.

Here's how the impact driver prevents driver tips from slipping out of screw heads: When the screw bites into the wood and becomes hard to turn, the impact drive mechanism causes the driver bit to automatically reset itself in the screw head several times per second -- making a rat-tat-tat sound similar to the noise you hear when a mechanic loosens the wheel nuts on your car. The sound comes from the driver repeatedly rotating the screw a partial turn forward, then a quick, little turn backwards; this keeps the driver tip firmly seated in the screw head. The difference this makes is tremendous. Impact drivers are usually smaller and lighter than comparable drill drivers. Once you've used one to drive screws, you'll never want to go back to an ordinary drill.

To read more about choosing and using the right drills and drivers, check out Steve Maxwell's Tool Talk column in the December/January 2006 issue of Mother Earth News.