What Power Requirements should I look for when
Choosing an Electric Drill?
By: The Working Man
Most electric drills that have a cord are rated using
amperage (AMPs). The most common corded drills range in
power from three amps to ten amps.
Generally the more amperage an electric drill
has the more
power the drill has available to work with. When a drill has
high amperage this should be reflected throughout the drill
by a sturdier casing, robust bearings and gearbox, etcetera.
When a low amperage drill is used hard it will work at its
maximum amperage all of the time, working the bearings of
the drill to the limit, while a drill with a higher amperage
doesn't work as hard to do the same job, reducing wear and
tear on the machine.
If you intend to use your power drill a lot for tough jobs
you should buy a drill with a slightly higher AMP rating
than necessary. This way it will have more than enough power
to spin the drill bit at the power needed to get the job
done, which will in turn make the drill motor last longer.
Cordless drills are more often than not rated by voltage
which is based on the power supplied by the drill's battery.
The more voltage the drill has available the more powerful
the drill. Cordless electric drills range in volts from two
volts all the way up to thirty-six volts.
Most often cordless drills that rate twenty-four volts or
thirty-six volts are used by professionals and have more
power than needed by most do-it-yourselfers.
The average home-owners can get any job around the house
done with a 14.4 volt drill, however some also keep an
eighteen volt cordless drill on hand for when heavier
drilling is needed.
In any case it is an advantage to have a spare battery,
already charged, if you intend to work for extended periods.
There are different types of batteries used for different
models of electric drill, the two common types are: Nickel
Cadmium (Ni-Cd) and Nickel Metal Hydride (Ni-Mh).
The most common of these two is the NiCd battery, which has
mainly been used due to its toleration of deep discharge for
long periods. The newer NiMh type batteries have a higher
capacity and less toxicity and seem to be generally more
However the NiCd battery has a slightly lower internal
resistance and therefore can achieve a higher maximum
discharge rate, which is important in the case of power
tools, and is thus still the most common preference in
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