Holesaws & Arbors

About Holesaws & Arbors

Holesaws and arbors are essential power tool accessories for cutting precise circular holes in a wide variety of materials, from timber and metal to plastics, tiles, and masonry. Whether you're a professional tradesperson working on site or a DIY enthusiast tackling home improvements, holesaws provide a faster and cleaner alternative to drilling multiple small holes or using jigsaws for circular cuts. The holesaw itself is a cylindrical cutting tool with teeth around its edge, whilst the arbor (sometimes called a mandrel) is the shank assembly that connects the holesaw to your drill or impact driver and includes a pilot drill bit to centre and stabilise the cut.

This category encompasses everything you need for holesaw applications: individual holesaws in various diameters and cutting technologies, arbors and pilot drills in different sizes and thread types, complete holesaw sets that provide multiple cutting diameters in convenient storage cases, and useful accessories like holesaw plugs for removing cut material and extension arbors for drilling through thicker materials. Understanding which type of holesaw and arbor combination suits your specific application is crucial for achieving clean, accurate cuts whilst maximising the lifespan of your cutting tools.

Modern holesaws are manufactured using several cutting technologies tailored to different materials. Bi-metal holesaws are the most versatile option for general use in wood, metal, and plastic. Tungsten carbide tipped (TCT) holesaws excel when cutting abrasive materials like chipboard, fibreglass, and even aerated concrete. Diamond-coated holesaws are specialised for ceramic tiles and porcelain, whilst dedicated masonry holesaws tackle brick and concrete. Leading brands such as Milwaukee, DeWalt, Bosch, Makita, and Starrett offer comprehensive ranges that cover every application from electrical installation work to plumbing, carpentry, and construction.

Jargon Buster

• Arbor (Mandrel): The connecting shank assembly that attaches the holesaw to your drill and includes a pilot drill bit. Arbors come in different thread sizes (typically 1/2"-20 UNF or M14 metric threads) and hex shank sizes (7/16" or 11mm) to match different holesaws and power tools.
• Pilot Drill Bit: The centre drill bit that protrudes from the arbor to create a guide hole and stabilise the holesaw during cutting. This prevents wandering and ensures accurate hole placement.
• Bi-Metal Construction: Holesaws made from two metals - typically a high-speed steel (HSS) cutting edge welded to a spring steel body. This combination provides the hardness needed for cutting whilst resisting tooth breakage and cracking, making them suitable for both wood and metal.
• Variable Pitch Teeth: Holesaw teeth with alternating tooth sizes that reduce vibration, improve cutting speed, and produce smoother holes, particularly effective when cutting metal.
• Slug Removal: The process of extracting the circular cut-out (slug) from inside the holesaw after cutting. Many holesaws feature slots or ejection springs to facilitate this, whilst separate holesaw plugs are available as accessories.
• Depth of Cut: The maximum thickness of material that can be cut in one pass, determined by the depth of the holesaw cup. Standard holesaws typically offer 38-42mm depth, whilst deep-cut versions extend to 60mm or more.

Who Uses Holesaws & Arbors?

• Electricians and Sparkies: For cutting holes through joists, studwork, and panels for cable runs, back boxes, downlighters, and electrical accessories
• Plumbers and Heating Engineers: Drilling through floors, walls, and units for pipework, waste pipes, radiator pipes, and service penetrations
• Carpenters and Chippies: Creating openings for locks, door furniture, ducting, extractor fans, and decorative features in timber
• Kitchen and Bathroom Fitters: Cutting holes in worktops for taps and sinks, tiling applications, and service access points
• HVAC and Ventilation Installers: Drilling holes for ducting, vents, and extraction systems through various building materials
• Shop Fitters and Joiners: Installing display lighting, cable management systems, and fixtures requiring precise circular apertures
• Maintenance Engineers: General facilities maintenance and repair work requiring hole cutting across diverse materials
• DIY Enthusiasts and Home Improvers: Installing door locks, light fittings, waste pipes, and undertaking general home renovation projects

How to Choose the Right Holesaws & Arbors

Material Compatibility: Select the appropriate holesaw technology for your application. Bi-metal holesaws suit wood, plastic, and thin metals. TCT holesaws handle abrasive materials like MDF, chipboard, fibreglass, and non-reinforced masonry. Diamond holesaws are essential for tiles and porcelain, whilst dedicated masonry holesaws with carbide grit tackle brick and concrete.

Diameter Requirements: Consider the range of hole sizes you regularly need. Individual holesaws typically range from 14mm to 210mm diameter. If you require multiple sizes, holesaw sets offer better value and include arbors and pilot drills. Common sets include sizes for electrical work (downlighter holes), plumbing (standard pipe diameters), or general trade use.

Arbor Compatibility: Ensure your arbors match both your holesaws (thread size) and power tool (shank size). Standard arbors fit holesaws up to approximately 32mm, whilst larger holesaws require heavy-duty arbors. Some manufacturers use proprietary quick-change systems like Milwaukee's SHOCKWAVE or Starrett's Fast Cut, which speed up holesaw changes on site.

Depth of Cut: Standard holesaws typically cut to 38-42mm depth, adequate for most applications. When cutting through thicker materials like multiple stud walls or deep worktops, look for deep-cut holesaws (60mm+) or extension arbors that add length to your setup.

Power Tool Compatibility: Most holesaws are designed for use with standard drills, but if you work primarily with impact drivers, choose impact-rated holesaws and arbors that can withstand the additional forces. Brands like Milwaukee and DeWalt offer dedicated impact-rated ranges.

Build Quality and Brand: Professional-grade holesaws from established brands like Bosch, Makita, Starrett, and Milwaukee use superior materials, precision manufacturing, and advanced tooth geometries that deliver cleaner cuts and significantly longer service life compared to budget alternatives - crucial for tradespeople who rely on their tools daily.

Popular Accessories

• Holesaw Plugs and Ejectors: Spring-loaded tools that push cut slugs out of holesaws, saving time and preventing finger injuries
• Extension Arbors: Add length to reach through deeper materials or when working in confined spaces
• Replacement Pilot Drill Bits: High-speed steel or carbide-tipped replacement bits in various lengths for worn or damaged pilots
• Holesaw Storage Cases: Organised cases that protect holesaws and keep complete sets together on site or in the workshop
• Cutting Lubricants and Waxes: Specialist lubricants that reduce friction, heat, and wear when cutting metal, extending holesaw life
• Centring Guides and Jigs: Accessories that ensure accurate hole placement, particularly useful for repetitive work or difficult angles
• Quick-Change Arbor Systems: Proprietary systems from brands like Milwaukee and Starrett that enable rapid holesaw changes without tools
• Diamond Core Drill Bits: For applications requiring holes in concrete, masonry, or stone beyond standard holesaw capability

Safety Information

Kickback Hazards: Holesaws can jam suddenly, especially when cutting metal or when teeth become blunted, causing the drill to twist violently. This kickback can cause serious wrist, arm, or hand injuries. Always use a drill with a slip clutch or electronic kickback protection feature, and maintain a firm grip with both hands using the auxiliary handle at all times.

Personal Protective Equipment: Always wear safety glasses or goggles to protect against flying debris and metal swarf. When cutting materials that produce fine dust (MDF, fibreglass, masonry), use appropriate respiratory protection conforming to HSE guidelines. Heavy-duty work gloves protect hands when handling holesaws and sharp cut slugs, but never wear gloves whilst operating power tools.

Secure Workpieces: Never hold work by hand when using holesaws. Always clamp or securely fix materials before cutting to prevent movement that could cause the holesaw to jam or the workpiece to spin dangerously.

Electrical Safety: When drilling through walls or floors, use a cable and pipe detector to locate hidden electrical cables, water pipes, and gas lines before cutting. This is essential for preventing potentially fatal electric shocks or dangerous gas leaks. Always ensure your power tools are properly maintained and PAT tested in accordance with UK regulations.

Heat and Sharp Edges: Holesaws generate significant heat during use, particularly when cutting metal. Allow holesaws to cool before touching or changing them. The cut edges of holes, especially in metal, are extremely sharp and can cause serious lacerations. Deburr holes and handle cut material with appropriate care.

Correct Speed Settings: Use appropriate drill speeds for the material being cut. Metal requires slower speeds than wood to prevent overheating and premature tooth wear. Excessive speed can cause holesaws to overheat, lose temper, and fail catastrophically.

Frequently Asked Questions

What's the difference between an arbor and a mandrel?

These terms are used interchangeably in the UK trade - both refer to the shank assembly that connects the holesaw to your drill. The arbor/mandrel includes the pilot drill bit and threaded section that screws into the holesaw, plus the hex shank that fits into your drill chuck or quick-change holder.

Can I use the same holesaw for wood and metal?

Bi-metal holesaws are designed to cut both materials, but they'll wear faster when used on metal. For primarily metal work, choose holesaws with variable pitch teeth optimised for metal cutting. Use appropriate cutting speeds - slower for metal, faster for wood - and apply cutting lubricant when working with metals to extend holesaw life.

Why does my holesaw keep jamming or binding?

Jamming typically occurs due to blunt teeth, incorrect speed, insufficient pressure, or lack of lubrication when cutting metal. The pilot drill bit may also be worn, causing the holesaw to wander and bind. Ensure your pilot bit is sharp, use appropriate cutting speeds, maintain steady pressure, and clear swarf regularly. When cutting deep holes, withdraw the holesaw periodically to clear waste material.

How do I remove the cut slug from inside the holesaw?

Cut slugs can jam tightly inside holesaws. Many modern holesaws feature slots or ejection springs to help release slugs. Alternatively, use a dedicated holesaw plug tool (a spring-loaded accessory specifically designed for slug removal) or carefully lever out the slug with a flat-blade screwdriver. Never use your fingers as the edges are extremely sharp.

What size arbor do I need for my holesaws?

Standard arbors typically fit holesaws from 14mm to 30-32mm diameter. Larger holesaws (32mm+) require heavy-duty arbors with larger thread sizes and more robust construction. Check the thread specification of your holesaws - common sizes include 1/2"-20 UNF and M14 metric threads. Some manufacturers offer universal arbor sets that cover multiple size ranges and thread types.