Drills

• What will be the main function: screwing, drilling, or both?

• On what types of material will it be used? Wood, concrete, or metal?

• Who will be using it? A dedicated professional or occasional do-it-yourselfer?

• In what context will it be used and is mobility an issue? In the workshop or around the house? Inside, outside?

Distinctions in power drill terminology:

• The word drill usually refers to an electric drill with a cord and only one speed. Though they do screw, they are used primarily to drill, and the chuck accepts various types of shank.
• The power screwdriver is meant to screw, has one speed and takes hexagon-shaped shanks. Smaller than a drill driver, it is more powerful and the battery lasts longer. When it encounters resistance, it hammers in the direction of rotation to sink the screw more easily.
• The drill driver refers to cordless drills that operate with rechargeable batteries. They usually have two speeds and the chuck accepts various types of shank. Torque settings can be adjusted to screw as well as drill. The hammer drill takes an SDS or cylindrical shank, depending on the model. It has a minimum of two speeds and three modes, making it possible to drill, screw and work through concrete. It has an additional handle for increased control. In the “drill” mode, the bit hammers back and forth within the chuck, which strikes the concrete.
• The hammer drill takes an SDS or cylindrical shank, depending on the model. It has a minimum of two speeds and three modes, making it possible to drill, screw and work through concrete. It has an additional handle for increased control. In the “drill” mode, the bit hammers back and forth within the chuck, which strikes the concrete.

As is the case with most electric power tools, the choice is between corded and cordless drills.

Corded
The main advantages of a corded electric drill are power, speed (revolutions per minute, or RPM) and increased endurance.

• Power is measured in amps, generally between 3 and 7 amps; the higher the amp rating the more powerful the drill.
• Speed of the motor is between 400 and 3000 RPMs and is controlled by means of pressure on the trigger switch.
• Though proximity to an electrical outlet is necessary, it is always ready to use and can be used as long as you want. Extension cords are a must.

Cordless

• Its biggest advantage is mobility.
• More expensive models will give you equivalent power to corded electric models.
• You have greater flexibility with speed and torque control settings on cordless driver drills than corded drills.
• The speed selector allows you to adjust RPM, which can go from 400 to 1500 RPM, depending on the model.
• Battery life is affected by the demands of the job; the harder you work the drill, the quicker your battery will run out.
• Requires more than one battery; you should recharge one battery while you’re using the other.
• Power is determined by its voltage, generally between 7.2V and 36V, and aH (amps per hour), normally between 1.2aH and 3aH A higher voltage means more drilling power, and high amperage is translated into longer use.

Note: certain components may not be available on all drills. Components also vary between different electric drills and cordless drills.

1- Chuck
The drill chuck is the mechanism, with or without key, which holds the shank of the drill bit or screwdriver bit.

• The chuck key is used to open or close the drill chuck, mainly on corded electric drills. It locks the chuck and makes it more vibration-resistant.
• The keyless chuck is standard on cordless drill drivers and makes changing out the drill bit much faster.
• The SDS Chuck mechanism is found on certain hammer drills used for concrete.

The maximum chuck capacity is normally ½" but certain models offer 3/8" or even 5/8" on some hammer drills. Most drill and screwdriver bits can be inserted to 3/8" chuck.

2- Speed range switch
The speed selector means that you can choose between slow and high speeds on cordless drill drivers and hammer drills.

• To screw, choose a slower speed to avoid blunting the screw head, driving it too deep, or damaging the material you’re screwing into.
• To drill into wood, use a high speed; to drill into stone (with a hammer drill) or metal use a slower speed.

On electric drills, speed is generally controlled with the trigger and a hold button allows you to maintain a constant pressure.

3- Forward/reverse function
This switch determines the motion, either clockwise or counter clockwise. It means you can screw and unscrew, and also loosen drill bits more easily after you’ve drilled a hole.

4- Torque selection / clutch
The torque selection switch on cordless drill drivers means that you can adjust the torque setting. Torque is measured in pound inches and varies between 200 lb. inches on basic models and 600 lb. inches on high-end tools.

If the bit (drill bit or screwdriver bit) encounters too much resistance, the torque clutch will stop the drill. This will prevent you from stripping screw heads or sinking them too deep. Adjust the drill to a higher torque setting to prevent the drill from seizing when you're drilling thick or dense material

5- Trigger switch
Pressure on the trigger operates the drill and controls speed.

• On Cordless drill drivers equipped with a main speed selector (two speeds), pressure on the trigger is used for subtle variations in motor revolution.
• There is only one way to control speed on corded electric drills, and that is by means of pressure on the trigger, although you can also depress a button that will block the trigger so that speed will be locked into that position.

6-Battery
Cordless drills run on batteries. Each manufacturer has their own model, which is not compatible with other manufacturers’ batteries. Removable, the battery is housed in the battery terminal in the bottom of the handle. Some models have a gauge that tells you how much battery life is left; the life of the battery and time required for recharging vary.

Nickel and Cadmium batteries – Ni-Cad
These constitute the first generation batteries and are still available for old models still being made and sold, but not for newer models. Must be recharged when they’re low but not completely empty.

Nickel-Metal-Hydride batteries – NiMH
Widely available, these batteries are inexpensive and possess high energy density, very little memory effect.

Lithium-Ion battery – LiIon
Lighter and faster to recharge than the two previous batteries. Huge energy density and no memory effect, but they are very expensive and lose their charge in the cold.

7 –LED Worklight
Shines a light on the task at hand. Comes on automatically when the drill is in use.

8- Drill bit stand
Makes it possible to insert a drill bit directly into the drill.

Other components:

Electric brake
When you lift the switch, the drill bit stops immediately, increasing precision (i.e. not driving a screw too deep).

Laser level
Shows whether the drill is level; very useful when it’s necessary to drill or screw at a perpendicular angle.

Extra handle
Available on hammer drills, it gives you greater control and helps maintain forward pressure.

Materials	Power	Uses	Screw		Metal		Concrete, Stone, Brick*
Job			Visser	Drill	Screw	Drill	Screw and Drill
	3 to 4 amps	Heavy, long and repetitive jobs that require power, endurance and speed	Good	Very Good	Good	Good	Inadvisable
	5 amps +		Good	Best	Good	Good	Inadvisable
	9V or less	Furniture assembly Frames and shelves installation	Good	Good	Good	Good	Inadvisable
	12 – 14.4V	Hobbies and jobs around the house	Very Good	Very Good	Very Good	Very Good	Inadvisable
	18 – 36V	More demanding jobs Choice of advanced do-it-yourselfers and professionals	Very Good	Meilleur	Very Good	Best	Inadvisable
		Drill in concrete or brick	Very Good	Best	Very Good	Best	Best
		Perfect with different material except concrete or brick	Best	Inadvisable	Best	Inadvisable	Inadvisable

*It is possible to use a regular drill to bore small holes in concrete, but you’ll need to use a back and forth movement yourself with the drill.

There are many different accessories to choose from that can help with finishing the task, some with surprising functions.

Must-haves:

• Drill bits for wood, metal, concrete
• Driver bits: philips, slot, square, short, long
• Belt holster

Interest-specific:

• Hollow punch
• Depth stops
• Liquid pump
• Paint mixer
• Sanding bit
• Joiner
• Nut driver
• Drilling guides