Core Bits
Core Drill Bits for Professional Drilling
Core drill bits make round holes in concrete, masonry, stone, and tile. The bits are used in plumbing, electrical conduit, HVAC ducting, and anchor bolts. The coring drill bit is used to cut out a solid cylindrical plug, as opposed to a twist bit, which removes shavings. This is the correct type of bit to use for holes larger than those a twist bit can handle, where drilling with a hammer drill and chisel would otherwise take hours.
The tungsten carbide teeth on standard core bits are suitable for softer masonry such as brick or block. The difference is significant when cutting cured concrete, granite, engineered stone such as Dekton, as the diamond core bits have industrial diamonds embedded in a metal matrix. That's because diamond bits cut cooler, last longer with repeated use, and produce a cleaner edge, making them a number-one choice for any job that requires cutting rebar or aggregate.
Types and Applications of Core Bits
Core bits come in a variety of sizes from 3/16" for small conduit runs to 6" and larger for structural penetrations. When using wet-cutting bits, you must have a water line to wash away debris and regulate heat. Dry bits can be used with a vacuum attachment for interior work where water is not practical. Most of these bits are powered by a rotary hammer drill or a special core rig that has 5/8"-11 threading - anything larger than 2 inches should be used with a drill guide or stand to prevent the cut from going out of alignment.
Reinforced concrete requires a bit that's designed for the specific job. Segmented diamond bits with wider slots will remove debris more quickly and push through steel mesh. But be sure to apply less pressure when the bit encounters rebar than when it encounters steel mesh.
How to Choose and Maintain Core Bits
Use the same bit diameter as the pipe, conduit, or fixture to be inserted into the hole. Allow a small clearance to ensure the fitting slides in smoothly without binding. Also, before ordering, verify the thickness of the wall or slab because if it's too short, you'll need to repeat the process with a longer bit.
Always hold your workpiece securely, use eye and hearing protection, and never force a bit that is binding - that is typically where segments crack, or bits overheat. Keep water flowing steadily on we cuts. Let the tool do the cutting instead of leaning into it.
A well-maintained diamond core bit can go through hundreds of holes if you rinse it after wet cuts. Store it away from moisture and dress the segments on an abrasive block when the cutting slows down. Dull segments are usually the reason why a bit that once cut fast suddenly struggles.
Your Reliable Core Bit Supplier
Tool Academy stocks core bits from such brands as Pure Diamond Products, Alpha, Milwaukee, Linkwise, Diamond Productions, Russo, and Brevetti Montolit Spa. Choose from small hole saws, single bits by size, and full core bit sets. We can help you match the right bit and rig to your job, so don’t hesitate to contact us if you need some help.
