Drilling holes in concrete requires drills and drill bits designed specifically for use in masonry. With the proper drilling tool and drill bit, holes can be drilled in concrete to set concrete anchors, poles for fixtures and larger holes to install drainage pipes. Be sure to follow all manufacturer instructions for the tool and the drill bit chosen for your project.
Tool Selection and Use
A hammer drill, rotary hammer or core drill are special drills used for drilling holes in concrete. Hammer drills and rotary hammers are used for smaller holes, such as the size required for installing concrete anchors or creating small drainage holes. A core drill is used for larger holes such as the size required for installing a permanent patio umbrella, clothesline pole or cutting a hole for a drain pipe.
When using any type of drill to drill a hole in concrete, it is important to keep the drill straight to prevent the drill bit from shattering and prevent the hole from becoming elongated. An elongated hole will require patching, which will not be as strong as the surrounding concrete so anchors or fixtures may become lose over time.
Drill the hole slowly. Gentle pressure is all that is needed to guide the drill bit into the hole so the bit and drill can do the work. Exerting too much pressure can cause the drill bit to become overheated and shatter.
Concrete Drill Bits
Concrete drill bits, also called masonry drill bits, are used for drilling holes in concrete. Standard drill bits will dull quickly and may shatter from the friction and heat created while drilling. Large holes require diamond core bits specially made for drilling core holes in concrete. Smaller core bits are available that fit in a standard hammer drill or rotary hammer. Larger core bits are used only with a core drill.
While drilling concrete holes, safety glasses or goggles should always be worn. Fragments of concrete, concrete dust or a shattered drill bit can become embedded in the eye and require medical attention to remove. Large fragments have the potential to cause permanent blindness.