Core Drill Bit

Overview

A core drill bit is a hollow cylindrical bit, tipped with diamond segments, used to cut large-diameter holes straight through concrete, reinforced concrete, block and stone. Instead of pulverising the whole hole like a percussion bit, it grinds only a thin annular ring and removes a solid cylindrical core — which is why it can produce large, accurate, clean-walled openings far more efficiently than a standard drill.

Core bits are the tool of choice whenever a large opening is needed: passing pipes, conduit, cables and ducts through walls and slabs, creating openings for services, or drilling large-diameter holes for heavy chemical anchors and post-installed rebar starter bars.

Technical specification

How a core bit is used

The core bit is mounted on a suitable drilling machine (a hand-held or rig-mounted core drill) and, for larger diameters, is usually run wet — water cools the diamond segments and flushes the slurry out of the cut. The bit is advanced slowly and steadily so the diamonds grind their way through the material, leaving a smooth, round hole and a solid core that is removed at the end. The result is a clean opening with minimal cracking or spalling around its edge, which is important when the hole must later receive a pipe, sleeve or anchor.

Frequently asked questions