FORGEor concrete. Drills with selectable hammers are
sometimes known as combi drills.
Electric brake
When you pull the trigger, the chuck starts spinning,
but what happens when you release this? Some
drills continue to spin with the momentum of the
chuck, while others will apply a brake to stop the bit
almost instantly.
Handles
Just about every hand drill has a pistol-style handle,
but some also have a side handle that can be useful
when drilling into stubborn material, particularly when
using the hammer function.
Clutch
This limits the drill power. It’s mostly used when
using the drill as a screwdriver, to avoid stripping
screw heads.
Weight
You may find yourself drilling with the drill held in
awkward positions, and heavy drills can take their toll
on your arms.
Electrical supply
Drills can be corded or cordless. Corded drills are
generally more powerful (particularly at the cheaper
end of the spectrum), but obviously limit the places
you can drill to those within reach of a power socket.
Although cordless drills allow you to go anywhere,
they do limit the time you can drill to the capacity of
the battery. Having more than one battery means you
can drill with one while the other charges. Batteries
are measured in Amp hours (Ah).
The most confusing aspect of a drill can be
its power. The power of a drill is important, but
expressed in different (and sometimes confusing)
ways. It’s sometimes given in newton meters, and
sometimes in the maximum diameter hole that can be
drilled. For cordless drills, the voltage of the battery is
sometimes used to imply a particular power and, for
corded drills, the wattage of the motor is often given.
The power you need depends entirely on what you
want to drill. Even the weakest drill should manage
light woodwork and being used as a screwdriver, but
if you need to get through tougher materials, and
particularly if you want to make large holes, you’ll
need more power.
Don’t forget that Newton’s laws of motion mean
that you have to be at least as strong as your drill. You
can’t keep piling on the torque and expect to be able
to hold the drill or you’ll end up like a spinning top, so
there’s a natural limit for the amount of power that’s
useful in a drill. If you need to drill with more power
than you can hold, you’ll need a drill-press or some
other way of holding everything in place. Having good
quality, sharp drill bits can be as important as having
more power on your drill.
As a general rule of thumb, going less than 18 V
on a cordless drill will limit what you can drill (corded
drills are almost always more powerful).Above
The Milwaukee
M18CBLPD-402C has
got power and speed
in a small packageDon’t forget that Newton’s
laws of motion mean that
you have to be at least as
strong as your drill”
”