Hand and Electric Drills
Perhaps the most essential part of any tool collection, the drill is invaluable for many maintenance and repair tasks around
the home and can be either manually driven or electrically powered, although the latter is the more effective and the most common
of the two types of drill. The size of the drill is determined by the maximum drill bit shank that its chuck can accommodate.
Used primarily for boring holes in nearly all materials, the electric drill can also be used for a variety of other tasks, facilitated
by a number of accessories and attachments. These include sanding, screwdriving, grinding, and mixing paint to name but a few.
There are many different variants of the electric drill, and most of these are available as either mains operated drills, or battery powered cordless drills. Generally speaking, the bigger the chuck capacity, the larger the motor. As the power increases, the drill will run slower to give the greater torque or turning power needed in drilling larger holes in steel or masonry.
Depending on the purpose for which it was designed, a drill can be single speed, have two or three pre-set speeds, or incorporate a variable speed function. Variable speed is essential if using the drill to drive screws, and a reversing function allows the user to remove screws as well. Many drills also use adjustable clutches so that a screw can be driven without slowing the motor down when the screw seats, prolonging the motor's life.
The Different Variants of drills
(AKA Wheel Brace, AKA Eggbeater Drill)
Uses a hand operated crank handle to turn an interlocking gear, which in turn rotates the drill bit. With a quicker set-up time than the electric drill, the hand drill is most useful when you require only a small number of holes. Effective for drilling into wood, soft metal, and plastics, hand drills will generally accommodate most drill bits up to 6mm (1/4") in diameter in either keyed or keyless chucks, and can also be used for screwdriving. Some models incorporate two speed gears, double pinion, hollow handle to store bits, and fully enclosed gear mechanisms.
Essentially a larger version of the hand drill, incorporating a saddle-shaped plate to lean on so as to apply extra pressure whilst drilling. Most models are fitted with a side handle for extra stability, and many have twin speed gears.
Miniature Hand Drill
Particularly useful for fine work, such as model making, the miniature hand drill bores holes with very small, high-speed steel
bits. Useful for making pilot holes for small screws, some models have collets at both ends allowing the user to have different
size drills available without having to change the bit.
Similar to the hand drill, with the drill bit being rotated by manually cranking the handle whilst applying pressure. Effective
for drilling into wood, the brace will generally accept larger drill shanks than the hand drill, and can also be used for screwdriving.
Some models have a ratchet fitted to the chuck, allowing the user to drill/drive in places where a full rotation of the handle
is not possible.
With a similar chuck and ratchet construction to the standard brace, the joist brace is especially useful for drilling in restricted
spaces due to a frame that uses a lever at right angles to the line of the drill bit.
Mainly used for drilling pilot holes, the push drill uses very fine straight-fluted drill bits (known as drill points) that
are rotated via a repetitive pushing motion, that can be achieved single-handedly. Some models incorporate a hollow handle to store
the drill bits.
Electric Rotary Drill
The most basic of the electric drills, the rotary drill is used mainly for boring holes in a variety of materials. These can
be either mains-operated (i.e. corded), or battery-operated (i.e. cordless). Different functions incorporated into some models
include variable speed and reversing, and attachments can be used to enable different functions, such as sanding and grinding.
Similar to the rotary drill but with a greater torque, allowing the user to drive and remove screws as well as drill through
materials at a more rapid rate. Again, these can be either mains-operated or battery-operated (cordless), and different attributes
and attachments allow multiple functions.
Electric Hammer Drill
Designed for more heavy duty work than the standard electric rotary drill, the hammer drill not only rotates but also provides
a rapid hammering action rated in blows per minute (b.p.m.). This makes it ideal for drilling effectively into concrete and masonry,
particularly larger holes. Most models have variable speed hammering action, reversing action, and can be used as normal rotary
drills. Available as corded or cordless hammer drills, different models and attachments allow for different functions.
Electric Hammer Drill/Driver
(Impact Drill/Driver, Percussion Drill/Driver)
Similar to the electric hammer drill but allowing the user to drive and remove screws, available as either mains-operated or
Percussion drills tend to be higher power machines more suitable for professional users. As well as the rotate/hammer action, these
drills can be used with the rotation switched off to give just a hammer action for chiselling etc. The drill bits are usually SDS
- SDS is a system where the drillbit just pushes into the chuck and clicks into place. The torque is transmitted by splines, so the bit cannot slip. However the bits are appreciably more expensive than standard ones, as are the drills.
type with a special fitting into the chuck.
Electric Close-Quarters Drill
Useful for drilling in awkward places where a standard drill won't fit, the close-quarters drill is similar in specification
to the standard electric rotary drill, but with a 55° angled chuck. Operated via a finger control on the body, most models
come with reverse action and variable speed.
Named after it's so-shaped handle, the D-Handle drill provides a stable and powerful drilling action for heavy duty work, and
is particularly useful for jobs where a high level of torque is required.
Designed to drill holes in tight places where a standard drill won't fit, the right-angle drill is not too dissimilar to the
close-quarters drill, and can be corded or cordless. Some models incorporate an adjustable side handle for greater stability, and
a chuck key and wrench to allow the user to change the angle of the head.
(AKA Bench Drill, AKA Pillar Drill)
More accurate than any portable drill, a drill press uses a drilling head positioned above an adjustable workbench, both being fixed to a sturdy base. Most models include a clamp and a guide, allowing the user greater control when drilling.