How To Drill Into Concrete

Step 1

Buy a good drill machine. It is very important that you start with a good drilling machine! Features to look for are:

Variable speed
Hammering function
Depth setting
Good grip (a handle for your other hand helps a lot)
Power Starting with a cheap drill with less power will be very difficult and you will end up with holes that aren't deep enough, off the mark, or simply ghastly to look at. Don't be too cost-conscious, and go for a branded one (e.g. Bosch). It will be worth it.

Step 2

Get to know your machine. Read the user's manual. Understand what all the knobs and controls are for, and how to set the machine up. Make sure you are comfortable with your machine before moving on to the next step.

Step 3

Set the depth. Some machines will have a depth setting or depth control bar. Read the user manual and learn how to use it. If your machine does not have depth control, measure and mark the required depth with a pencil or masking tape.

Step 4

Hold your drill properly. Hold the drill with one hand like a gun, with your index finger on the "trigger". If the drill has a handle for your other hand to hold, use it. Otherwise put your other hand at the back of the drill.

Step 5

On the mark... Mark the point on the wall where you want to drill using a soft pencil.Mark it with a dot or a small cross. Make sure that your mark isn't too big.

Place your drill on the mark. Apply enough pressure to hold it in place, but do not press it too hard. You will learn the right amount of pressure from practice.
Drill using a low speed (if your machine has speed control) or in short bursts (if it doesn't). Make a shallow hole that will guide the drill machine so that you make the hole exactly on the mark.

Step 6

Drill. Using a high speed, drill into the shallow hole you made in the previous step. You will need to use some force against the wall, especially if the drill is a low power one. If your drill doesn't have an automatic hammering function, every ten seconds or so, pull your drill slightly out and press it back in again. If the drill takes long, pull your drill out and let it cool for a few seconds every now and then. Stop once you reach the desired depth.

Step 7

Troubleshoot. Sometimes, a drill doesn't go as expected. You might hit a "beam" or an especially hard piece of concrete. In such a case, insert a masonry nail into the hole and hammer. This will help break the concrete. Insert your drill back and continue drilling.

This video is a good demonstration of concrete drilling, and it also has a good explanation on the subject.

Tips

When going to purchase a masonry drill bit, there are two types. Multi-purpose (for use in a standard drill or hammer drill), and those that are exclusively for Rotary Hammer drills. These specialty bits are called SDS, SDS-MAX or Spline-Shank, and these bits cannot be used with a standard, non-rotary hammer type drill. Multi-purpose masonry bits can be used in either a hammer drill or standard drill, but generally not with a rotary hammer.
Do not bear down on the drill with all your strength. The bit could break.
When using a hammer drill, you only need to withdraw the bit occasionally to remove concrete dust.
Running a small amount of water over the area while drilling will reduce the heat of the bit and the friction between the sides of the concrete and the drill.
A good quality hammer drill will finish a 2-inch deep, 1/4 inch wide hole in concrete block in less than a minute. A standard drill will take much longer, and may not work at all in brick or poured concrete. Use a hammer drill where at all possible.
Screw into the mortar between blocks, if possible, as it is much easier to drill into mortar than concrete block. Always use lead anchors to hold the screws into place if you drill into the mortar, as screws set in mortar will work themselves loose over time. For some light weight applications (electrical boxes, conduit straps), plastic anchors (with regular screws) or "Tapcon" concrete screws (without anchors) are adequate. (Tapcon screws are easy to identify, as they are blue in color.) For any application where the screw will be subjected to weight (such as a bench, handrail or shelves) heavy duty lead anchors should be driven with a hammer after the holes are drilled and then screws driven into the anchors.
While it is possible to drill into concrete or brick with a standard drill, it is not advisable to try. The reason is that a standard drill acts on the principle of slicing into a fibrous material (like wood) or shaving off layers of metal (like aluminum and steel) and concrete/brick is not fibrous or composed of layers of material. Concrete/brick is a composite aggregate material (small rocks bound together with cement) for concrete, and minerals and stone bound together by heat for brick. To drill a hole in cement/brick requires two separate actions, hammering to break the aggregate, and drilling to scoop out the debris. This two stage process requires a hammer drill to accomplish properly. Usually attempts to drill into brick with a standard drill results in: 1) no holes actually being drilled, and 2) the motor of the drill overheating and the drill being ruined.
For very large holes (greater than 1/2 of an inch), or to drill many holes of any size, a rotary hammer is needed. These are large, piston hammer-drills, which have the advantage of being able to be used in "hammer only" mode. This mode allows them to be used to chip concrete and brick as well as drill into it. However, rotary hammers are usually very expensive and require special drill bits (SDS, SDS Max and Spline Shank being the most common). Nevertheless, to drill lots of holes, very big holes, or both, a rotary hammer is essential.
Holes of 2" diameter or greater can be easily drilled into masonary by a device called a core drill which can be rented.

Warnings

Protect your eyes with goggles when drilling and cleaning out the dust and debris.
The older the concrete, the harder it will be to drill.
When attempting to break aggregate with a masonry nail, take care not to drive the nail too deeply, otherwise it will be difficult to remove. Do not hammer with a flat-head screw driver. The wide edges of the screw driver's tip will produce gaps in the concrete which will weaken your anchor.
When using water, be careful not to get the motor of your drill wet.
Take care not to breathe in the dust. Use a dust mask.
Be aware that stone in concrete can explode and expel chips into your face.
Be aware that masonry bits get very hot. Wear heavy gloves when drilling into concrete or brick.
Hammer drilling into concrete or brick is very noisy. Wear ear protection even if you are only drilling a couple of holes.

Via wikihow