Buy Core Drill Bit Sets Online in Australia
Core Drill Bit Set Selection — Quick Reference
Core drills (annular cutters / mag drill cutters) enlarge or cut HOLES in steel by removing only the annular ring of material — NOT the full slug. Faster, less power, cleaner finish than twist drills on plate. Used in mag drill presses + drill presses.
| Core Drill Type | Best For | Cut Depth |
|---|---|---|
| HSS Core Drill (Standard) | Mild + low-alloy steel — workshop default | 25mm / 50mm cutting depth standard |
| HSS Cobalt Core Drill (M35/M42) | Stainless + tough alloys | 25mm / 50mm |
| TCT (Tungsten Carbide-Tipped) Core Drill | Hardened steel + cast iron + high production volume | 25mm / 50mm — long tool life |
| Solid Carbide Core Drill | Very hardened steel + production cutting | Per spec |
| Diamond Core Drill | Concrete + masonry + glass + tile | Per spec — wet cutting recommended |
| Pilot Pin (Centred) | Locates cutter on workpiece + ejects slug at completion | Per cutter size |
| Magnetic Drill Press (Mag Drill) | On-site drilling on steel plate + structural | Holds drill via magnetic base — portable |
Sizes: 12mm – 65mm common; mag drill range typically 12-90mm. Critical: Use cutting fluid (cutting oil drip or thread-on lubricator) — core drills run hot due to higher contact area than twist drills. Pilot pin MUST be installed before cutting — locates centre + ejects slug at completion. Vs twist drills: for holes 16mm+ in steel plate, core drills are 5-10× faster + use 50% less power than twist drills + leave a clean, burr-free hole. Brands: Sutton Tools, Bordo, Euroboor, Excision. Companion: annular cutters, drilling, cutting lubricants.
Core Drill Bit Sets
Core drills (hole enlargers or step drills for metal) are designed to enlarge existing holes to a precise finished size — removing only the annular material from the existing bore without removing the full slug from a solid workpiece. AIMS Industrial stocks core drill sets in HSS and TCT for use in drill presses and magnetic drill presses on steel plate and structural sections.
Core Drills vs Twist Drills for Hole Enlargement
Enlarging an existing hole with a twist drill is problematic — the chisel point at the tip of a twist drill is designed to cut from the centre out, and when presented to an existing hole it has nothing to cut at centre, causing chatter, tool grab and a poor-quality oversize hole. A core drill has a flat or countersunk centre with cutting edges arranged only on the annular zone, allowing it to enlarge the existing bore cleanly and accurately without chatter. This makes core drills the correct tool for opening punched or pre-drilled holes to a precise bolt or pipe clearance size.
Applications
Core drills are used in structural fabrication to bring punched holes to exact bolt clearance diameters, in plumbing and HVAC installation to open pre-cut holes in steel frames for pipe penetrations, and in any situation where an existing hole needs to be accurately enlarged to a specific size. Step drills (multi-diameter cone drills) serve a related function in thinner sheet materials, cutting clean holes in sizes from 4mm to 30mm from a single tool.
Set Coverage
Core drill sets typically cover hole enlargement from 14mm to 60mm diameter, addressing structural and mechanical fastening applications. For help selecting the right core drill for your material and application, contact our team. AIMS Industrial has been supporting Australian industry since 1988.
People Also Ask — Core Drill Bit Sets (Hole Saws)
Q: What's a core drill bit?
A core drill bit (also called a hole saw or hole cutter) cuts cylindrical holes by removing the circumference of the hole, leaving a solid 'plug' or 'slug' in the middle. Much faster than twist drills for larger holes (typically 14mm+). Available in: bi-metal (steel teeth on flexible body for wood/plastic/light metal), TCT (tungsten carbide teeth for thicker steel and stainless), diamond core (for masonry, concrete, tile, glass). See [Hole Saw Guide](/blogs/product-guides/hole-saw-guide).
Q: Bi-metal or TCT hole saw?
Bi-metal hole saw: workshop standard for wood, plastic, light steel, aluminium. M3 cobalt teeth on flexible spring steel back. Cuts efficiently up to 6mm steel. TCT (tungsten carbide tipped) hole saw: heavier-duty teeth for thicker steel, stainless, and abrasive materials. Cuts 12mm+ steel reliably. For workshop daily use covering wood and light metal: bi-metal. For sustained steel work or thicker sections: TCT. Diamond cores for masonry, concrete, glass — different category.
Q: What sizes come in a hole saw set?
Common workshop sets: 13-pc set (typically 16, 19, 22, 25, 29, 32, 35, 38, 44, 51, 57, 64, 76mm). 17-pc set adds 19, 25, 32, 51, and metric sizes. Premium sets include arbor/mandrel, pilot drill, and assorted hole saws. For workshop daily use, a 13-pc bi-metal set covers most needs. Add specialty sizes (very small or very large) individually. For trade vehicles, smaller more portable sets.
Q: How do I use a hole saw correctly?
Mark the centre of the hole. Apply slow steady pressure (let the saw do the work). Use cutting oil on metal (extends saw life dramatically). For deep holes, withdraw periodically to clear chips. For thick material, drill from both sides to prevent chip-out on the back. Use moderate drill speed — too fast burns teeth. Wear safety glasses + gloves. Don't side-load — hole saws shatter under side stress. See [Hole Saw Guide](/blogs/product-guides/hole-saw-guide).
Q: Can I sharpen hole saws?
Bi-metal: not practically — the small flexible teeth are complex to regrind. Replacement is more economic than sharpening. TCT: limited sharpening possible by specialty grinding services — generally not economic for workshop one-off use. Diamond cores: cannot be sharpened (diamond plating wears off). For all hole saws, treat as consumables — replace when teeth are dull or damaged. Premium brands (Bordo, Champion, Saber) deliver longer service per unit cost.
Q: Why would I use a core drill bit instead of a twist drill for holes over 16mm?
A core drill bit only cuts an annular ring around the edge of the hole rather than removing the full cross-section like a twist drill does, so it needs far less torque and power to punch through — typically 5-10 times faster and using about half the power of an equivalent twist drill for holes over 16mm.
Q: Is a magnetic drill press better than a hand-held core drill bit for steel plate?
For steel plate work, yes — a magnetic drill press holds the bit securely against the plate with far more rigidity than hand-held drilling can manage, and it opens up a wider practical size range (roughly 12-90mm with core bits) than you'd comfortably manage by hand.
Q: Does a core drill bit need lubrication when cutting through steel plate?
Yes — cutting fluid is essential when using a core drill bit through steel plate. It keeps the cutting edge cool and clears swarf from the annular cut, and running dry significantly shortens the bit's life.
Q: What's a pilot pin and why does it matter on a core drill bit?
The pilot pin centres and guides the core drill bit at the very start of the cut, keeping it tracking true instead of wandering across the plate surface. It needs to be fitted and set correctly before you start cutting, not added partway through.
Q: Can core drill bits cut concrete or masonry?
Most core drill bit types — HSS, HSS Cobalt, TCT, solid carbide — are built for metal cutting. For masonry or concrete, a diamond-tipped core bit is the type to use instead; it's a distinct category from the metal-cutting core bits, so check you've got the right type for the material before you start.