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Holesaw

18/11/2025
by Rick Coleman
Holesaw

G'day! You're in the middle of a reno, ready to run some new plumbing pipes or install a new set of downlights. You grab your drill, look at your biggest drill bit, and realise it's about as useful as an ashtray on a motorbike – it's just not big enough.

Trying to cut a big, round hole with a jigsaw is a recipe for a wobbly line that looks like a dog's breakfast. For a clean, fast, perfectly round hole, you need the right tool for the job. You need a holesaw.

So, What is a Holesaw, Exactly?

A holesaw (or 'hole saw') isn't a single drill bit. It's a clever, multi-part system that works as a team. It's made of three key bits:

  1. The Holesaw (The 'Cup'): This is the main part. It's the big, round, cup-shaped blade with the teeth that does the actual cutting.
  2. The Arbor (or Mandrel): This is the shaft that locks into your drill's chuck. The holesaw cup screws onto this arbor.
  3. The Pilot Drill Bit: This is a standard twist drill bit that sits in the centre of the arbor. This is the real hero – it drills a small hole first to keep the whole thing perfectly centred and stops the big saw from "walking" all over your wall.

It's the fair dinkum, go-to solution for any tradie or DIYer who needs to cut a clean, circular hole in just about any material.

The Ripper Benefits: Why You Need One

  • It's the Only Way to drill a clean, large-diameter hole (e.g., from 19mm up to 150mm+).
  • It's Versatile: You can get holesaw cups for timber, metal, plastic, and even tiles.
  • It's Clean: It cuts a neat 'plug' or 'slug' out of the material, leaving you with a schmick, round hole.

Choosing Your Weapon: The Main Types

This is the most important part, mate. You can't use a timber bit on hard steel. You've got to match the blade to the job.

1. Bi-Metal Holesaw (The All-Rounder)

This is the one you'll find in every tradie's kit. It's a tough, flexible blade with high-speed steel (HSS) teeth.

  • Best for: Timber (pine, hardwood), plasterboard (Gyprock), plastics (like conduit), and thin metals (like aluminium or sheet steel). A good electrical wholesaler will stock these as the standard for electricians.

2. TCT (Tungsten Carbide Tipped) Holesaw

This is the heavy hitter. It has a few, very aggressive, tough-as-nails carbide teeth.

  • Best for: Hard, abrasive materials. Think fibre cement sheeting, MDF, fibreglass, and thicker metals. It's much faster and tougher than a bi-metal bit for these jobs.

3. Diamond Holesaw (The Specialist)

This one doesn't have "teeth" at all. Its edge is coated in industrial-grade diamond grit.

  • Best for: This is the only choice for drilling into hard porcelain tiles, glass, or stone. It grinds the material, it doesn't cut it.
  • Hot Tip: You must use these with water to keep them cool, or you'll knacker the bit in seconds.

A CRITICAL Safety Warning: DIY vs. Pro

Righto, let's get dead serious for a sec.

  • DIY (Have a go!): Using a holesaw to cut a hole in timber, plasterboard, or a bit of metal in your shed is a classic (if careful) DIY job. Wear your safety glasses, mate!
  • PRO ONLY (Stop!): What if you're using that holesaw to cut a 90mm hole in your ceiling for a new 240V downlight?

Cutting the hole is one thing, but the job of reaching into that ceiling, pulling down the 240V wiring, and connecting the new light fitting is 100% NOT A DIY JOB.

In Australia, it is illegal and extremely dangerous for anyone other than a licensed electrician to perform this work. A simple mistake can lead to a fatal electric shock or a house fire. Don't be a galah.

A Professional Job Needs Professional Gear

A licensed professional knows that a schmick, reliable job depends on using high-quality, trade-grade tools and components. They won't risk their reputation on a dodgy, cheap holesaw that cuts a hole on the piss. They get their gear from a trusted electrical wholesaler.

As one of Australia's most comprehensive electrical wholesaler and supplier networks, Schnap Electric Products stocks the lot for the professional installer. They've got a massive range of high-quality holesaw kits (Bi-Metal, TCT, and Diamond), alongside all the professional-grade, compliant components that a qualified professional needs to install into those holes – from IC-rated LED downlights and weatherproof junction boxes to conduits and cable glands. For a job that's safe, compliant, and built to last, the pros start with quality gear from a supplier like Schnap Electric.