It’s usually worth it to pay more for a more powerful hammer drill (at least 7 to 10 amps) from a well-known brand. [3] X Research source Other beneficial features include a speed setting, depth stop, comfortable grip, and a second handle for your other hand.
Follow all safety instructions. This includes wearing safety goggles to protect your eyes from chips of concrete, hearing protection, and heavy gloves to protect your hands from abrasion and hot drill bits. A respirator is also recommended for larger projects that create a lot of dust. Hammer drills can be switched to a non-hammering drill setting simply by turning the collar.
Rotary hammers require specialty drill bits, called SDS or SDS-MAX (for holes up 5/8" in diameter) or Spline-Shank (for holes 3/4" or larger). [5] X Research source Reinforced concrete is much more difficult to drill if you need to drill deeper than the steel rebar. Switch to a special rebar-cutting bit once the drill hits metal. [6] X Research source Slow down and pause occasionally to prevent overheating.
Because concrete is a hard, dense material, screws embedded 1 inch (2. 5 cm) deep are sufficient for hanging light-weight objects. Heavier-duty projects require longer screws or concrete anchors, which should list the minimum embedment on the packaging. Add an additional ½" (6 mm) to the embedment to allow room for the dust that accumulates during drilling. [8] X Research source You can reduce this length if you plan to remove the dust afterward (described below). [9] X Research source For hollow concrete blocks or thin concrete surfaces, check the fastener specifications. Some plastic anchors require a solid backing, and will fall out if you drill through the other side.
If the project requires a large diameter drill bit, consider using a smaller drill bit for the pilot hole. This will increase the drill’s stability. [11] X Research source
Apply enough pressure to hold the drill in place, but do not force it forward (this increases wear on the bit and can even break it). You will learn the right amount of pressure from practice.
Occasionally stop the drill and pull it out to let it cool for a few seconds. This is especially important for ordinary rotary drills, since they can easily overheat during a lengthy drilling process. You may feel a little bit of recoil and kick from the drill.
If you see sparks or see metal, you have hit rebar. Stop drilling immediately and switch to a rebar-cutting drill bit until you are past the obstruction.
Concrete dust can be hazardous to breathe in, so make sure you wear a mask during this process. You can also extract the dust by using a damp cotton swab to wipe it out.
