Diamond core drill bit

Diamond core drill bits are purpose-built for cutting round openings in concrete and masonry — typically for flush-mount electrical boxes, switch boxes and pipe penetrations. The standard diameters match the common dimensions of electrical and plumbing fittings, so a single drilling pass produces a perfectly sized opening.

Round openings for electrical and plumbing work

Electricians and installers use core drill bits daily for recessing outlets, switches and junction boxes into concrete or masonry walls. The bit cuts a circular core out of the material, which you then remove with a chisel or hammer. The most common diameter is 68 mm, matching standard switch boxes, but larger sizes are available for double boxes, extraction vents and pipe penetrations. A drilling template helps position multiple openings at the correct spacing.

Dry or wet, depending on the material

In lightweight concrete and sand-lime brick you can drill dry without issues. In heavily reinforced concrete, wet drilling is advisable because the rebar generates extra heat. When drilling dry, always combine the core bit with dust extraction — the volume of dust from cutting a box opening is substantial. Monitor the maximum RPM of your machine and adjust the feed rate to the material for optimal segment life.

Fast installation, clean openings

For runs of multiple boxes side by side, a drilling template that locks the exact position and spacing is invaluable. It ensures every opening lands in precisely the right spot without measurement errors, speeding up repetitive work considerably.

With a quality core drill bit you cut a clean, round opening in under a minute. That saves significant time compared with chiselling, and the result is far neater. Our core drill bits are compatible with common SDS-plus and SDS-max chucks — verify which fitting your machine uses and select accordingly. Browse our range and choose the diameter that matches your flush-mount boxes and piping system.

Our core drill bits are compatible with common SDS-plus and SDS-max chucks. Verify which fitting your machine uses before ordering to ensure a perfect match.