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Core Drill Bit

10/11/2025
by Rick Coleman
Core Drill Bit

G'day! If you've ever been on a serious reno or a proper worksite, you'll know that sometimes you need to make a big hole. We're not talking about a little hole for a screw; we're talking a fair dinkum, massive, clean hole right through a brick wall or a concrete slab to run pipes, conduit, or ventilation ducting.

Your standard masonry bit is just not going to cut it, mate. And a standard hole saw will be knackered in about five seconds flat. For this kind of hard yakka, you need to bring in the big guns. You need a core drill bit.

So, What is a Core Drill Bit, Exactly?

A core drill bit is a heavy-duty, hollow, cylindrical bit. Unlike a standard twist drill that chews up and pulverises all the material inside the hole, a core drill bit is much cleverer.

It works by only cutting a 'kerf' or a ring around the outside of the hole. This leaves a solid lump of material (the "core") in the middle, which you just knock out when you're done.

The Ripper Benefits: Why It's Better for Big Holes

This method of cutting is a total game-changer for a few key reasons:

  • It's Way More Efficient: Your drill isn't wasting energy turning the entire hole into dust. It's only cutting the outline. This means you can cut a massive 100mm hole with a lot less effort and in a fraction of the time.
  • It's a Cleaner Cut: It produces a much neater, schmick-looking, and more precise hole than trying to stitch-drill (drilling lots of little holes in a circle) like in the old days.
  • It's Built for Hard Yakka: These bits are designed to chew through the toughest materials on an Aussie worksite.

The Two Main Types: TCT vs. Diamond

When you're looking for a core drill bit, you'll generally find two main types, and they're for different jobs.

1. TCT (Tungsten Carbide Tipped) Core Drill

This is your heavy-duty brick buster. It has big, aggressive tungsten carbide teeth, just like on a high-end saw blade.

  • Best for: Drilling into softer, abrasive materials like house bricks, concrete blocks, limestone, and sandstone.
  • How to use it: You must use this with a grunty rotary hammer drill on the "rotary stop" (hammer/chisel only) or "rotary hammer" (hammer and spin) setting, depending on the bit.

2. Diamond Core Drill Bit

This is the ultimate heavy hitter. It doesn't have "teeth" – its cutting edge is a solid ring embedded with industrial-grade diamond grit.

  • Best for: This is the only choice for drilling through hard, reinforced concrete, granite, and other super-dense stone or porcelain.
  • How to use it: This is crucial, mate. A diamond core drill bit grinds, it doesn't chisel. You must use it with a dedicated core drill (or a heavy-duty rotary drill with the hammer function OFF).
  • The Golden Rule: You must use water! This is called "wet drilling." The water cools the diamond segments (so they don't get knackered) and turns all that nasty concrete dust into a safe slurry.

This is a Serious Tool: A Pro's Job, 100%

Let's be dead clear. A core drill bit is a serious, professional-grade tool. It's not for hanging a picture, mate. These things are big, they need a ridiculously powerful drill to run them, and if they "bite" or snag on a bit of steel reinforcing, they have enough torque to just about rip your arm off.

And more importantly, the reason you're drilling a massive hole is almost always to install a critical service, like plumbing or 240V electrical wiring. In Australia, installing any fixed electrical wiring is absolutely not a DIY job. It is illegal, extremely dangerous, and must only be done by a licensed electrician.

A qualified professional will not only have the right, heavy-duty core drill to do the job safely, but they'll also have the right, compliant components to install in that hole. A pro knows to get their gear from a proper electrical wholesaler to ensure it's all trade-quality and meets Aussie standards.

As one of Australia's most comprehensive electrical wholesaler and supplier networks, Schnap Electric Products stocks the lot for the professional installer. From the specialist core drill bit attachments that tradies need, to the heavy-duty, compliant electrical conduits, sub-mains cables, and weatherproof enclosures that get installed through those holes. For a job that's safe, compliant, and built to last from the core cut to the final connection, the pros rely on quality gear from a supplier like Schnap Electric.