How to shop for a drill

Drill drivers spin clockwise and counter-clockwise at varying speeds, with an adjustable clutch that automatically regulates the depths at which screws are driven.

If you had to choose just one power tool to help with home maintenance chores, an electric drill would be a great option. But for many people buying any kind of power tool involves an excursion into culturally-foreign territory. Do you feel like store-wide impostor alarms will sound if you step into the power tool aisles in a big box hardware store? Worried that the check-out clerk is going to ask to see your Power Tool Acquisition Certificate when you go to pay for the thing? Do you have recurring nightmares where crowds of people wearing dirty plaid shirts and shamefully low-slung, baggy jeans deride you for asking simple questions about power tools?

There's comfort in numbers, so know that you're not alone. Lots of people are intimidated by tools. But let me fill you in on a secret. Most of the pros are almost as confused about new tools as beginners are. They're just better at hiding it. The truth is, power tools are getting better so fast that it's difficult to keep up with the advances. But that's okay. All you need to know are the basics of buying a good drill. And that's information that will open up a whole new world of home improvement possibilities for you.

The first thing to understand is that drills are useful for more than just making holes. In fact, you may only use a drill for this job half the time or less. The rest of the time you'll be driving screws in or out. That's why you should consider a particular configuration of tool called a drill driver. It spins clockwise and counter-clockwise at varying speeds, with an adjustable clutch that automatically regulates the depths at which screws are driven. And most drill drivers are battery operated, which brings you to the main decision you face when selecting a particular model. Corded or cordless?

Cordless drills were pretty wimpy when they first hit the market more than 20 years ago - nothing more than toys, really. But they've come a long way since. They're now so good that higher voltage units like the 12, 14.4 and 18 volt models can replace a conventional corded drill for most household jobs. While there's no doubt that drill drivers are king of the general-purpose home improvement drill tools, there's also a little-known issue you need to consider. If you're looking for a tool exclusively for driving screws, then consider something called an impact driver. These look like drills and are made by all tool manufacturers, though rarely marketed to home owners. That's too bad because they do an outstanding job at the specific task of driving screws. And to understand why, you need to see some details.

When you drive any screw with a power tool, there's a tendency for the screwdriver bit to disengage from the screw head, spinning around ineffectively as it does. This is called camming-out, and both the screwhead and driver bit gets mashed-over pretty quick when it happens. The remedy is to drive the screw in short bursts, by pressing and releasing the drill's trigger every second or two. But even still, screwdriver bits still come out of screw heads regularly, no matter how skillfully you drive them. The good news is that an impact driver virtually eliminates the problem of cam-out because it doesn't just spin. It automatically delivers torque to the screwhead in short bursts, allowing the screwdriver bit to reset itself in the screwhead a number of times each second. This makes screwdriving a snap and cam-out virtually non-existent. Trouble is, the business end of an impact driver isn't equipped to hold drill bits for boring holes.

Cordless drill drivers and impact drivers are serious performers, but they don't come without an added cost. You might spend twice as much on the purchase of a cordless drill than on an equivalent corded model, so the convenience of tangle-free operation should be pretty important to you if you choose cordless. Also, cordless tool batteries typically last three to five years before they won't accept a charge any more. And the cost of replacement batteries a serious consideration.

The nickel-cadmium (nicad) and nickel metal-hydride (ni-mh) batteries behind today's awesome cordless performers don't last forever. Eventually they lose their ability to hold a charge, with the higher voltage battery packs having a shorter life because of the higher internal temperatures generated during charge/discharge cycles. And with the cost of a new 14.4 or 18 volt battery pack sometimes exceeding $100, you've got to ask yourself if you really need cordless convenience. Sure, it's cool, but that's nothing to base a wise tool purchase on. And if you do decide on cordless, understand that dead nickel cadmium battery packs must be disposed of as toxic waste. Cadmium is a hazardous metal that's very persistent in the environment.

A final word of advice about tool choice. The market for power tools is fierce these days, and tool manufacturers everywhere want your business. One way they try to sway you is with no-questions-asked return policies. Many companies (though not all) allow you to try their tools risk-free at home, then return them for a full refund without any reason except that you're not pleased. Details vary from make-to-make, so check with your retailer before you buy. Typical return periods extend from 1 to 3 months - more than enough time to start feeling like an initiated power tool user before the next time you saunter down those once intimidating aisles.