There are many different options available when choosing a power drill. And for every brand or model of drill that exists is a different opinion about which one is best. Ultimately choosing the right drill for you is a simple matter of personal choice and preference. Here are some basic guidelines for selecting the drill that best suits your individual needs.
Speed is one of the factors to consider when purchasing a drill. A drill that runs at higher speeds is more capable of cutting through material. Most low end drills run at a single constant speed, usually around 300 rpm's. Many medium to high end drills will feature a switch that allows the drill to run at either high or low speeds. Most low speed settings will run around 300 rpm's and high speed settings around 800 rpm's. Some higher end models may run as high has 1,000 rpm's. Some drills will have a variable speed trigger. These models will run from 0 to 800 rpm's based on how hard you squeeze the trigger. It is difficult to rate this feature as the sensitivity of the trigger ultimately determines the drill speed and will vary greatly from drill to drill.
Another factor in choosing a drill is clutch. Most electric drills do not feature an adjustable clutch, however some higher end models do. Cordless drills often do. A variable speed clutch allows you to control how much power is being exerted by the drill. For example, if you set the clutch to a low setting and pulled the trigger all the way down, you would only get a small amount of power. The clutch setting prevents the motor from turning faster than the setting allows. This helps prevent you from stripping or overdriving screws.
Power is another consideration. For a cordless drill, power is determined by the voltage of the battery. There are many different choices for voltage, most ranging from 6 to 18 volts. A higher voltage means more power, which means more torque. For light hobby applications a small voltage drill is probably sufficient. For remodeling or construction, however, the highest possible voltage will allow for much more versatility.
Battery life or type is important if buying a cordless drill. Many of the drills available today have Nickel-metal-hydride (NiMH) batteries. This represents the latest in power battery technology. Batteries used to be nickel-cadmium (Nicad), however cadmium is highly toxic and makes disposing of old batteries risky. All cordless batteries come with a battery charger. Some chargers may recharge a battery in as little as 15 minutes while others may take up to three hours. Faster is not necessarily better as fast charging may create excess heat, which may in turn damage the battery. For the average home owner, longer charge times may extend the life of the battery.
The last big question is whether to buy a cordless or electric drill. Cordless drills are certainly more convenient, especially for anyone working on ladders or outdoors. The problem is that once the battery dies you have to recharge it before you can continue working. One solution is to always have one or two spare batteries. This way one can be charging while one is being used. Keep in mind that as the battery drains the drill's power will gradually decrease. Electric drills maintain an even power output. Though the cord may become tangled or be a minor inconvenience, you are assured that so long as you have access to an outlet your drill will preform without any loss of power. Another feature of cordless drills is key-less chucks. Most electric drills require the use of a chuck key to change bits. A key-less chuck allows the operator to simply unscrew the chuck by hand. This becomes quite a time saver for projects where many different bits are to be used.