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.