Magnetic Drills

About Magnetic Drills

Magnetic drills, often called mag drills or magnetic drilling machines, are specialised power tools engineered for precision drilling in metalwork applications. Unlike conventional pillar drills that require fixed mounting to a workbench, these innovative machines use powerful electromagnetic bases to attach directly onto steel and metal surfaces. This unique design allows tradespeople to bring workshop-level accuracy to fabrication sites, structural steelwork, and engineering projects where materials cannot be moved to a stationary drill press.

The magnetic base creates an incredibly strong bond with ferrous metals, enabling these tools to work safely on horizontal, vertical, and even overhead surfaces. Most magnetic drilling machines are designed to work with annular cutters – hollow drill bits that remove only the outer edge of material, creating faster, cleaner holes with less effort than standard twist drills. However, many models feature interchangeable arbors or chucks, allowing them to accommodate conventional drill bits for smaller diameter holes and pilot drilling applications.

Modern magnetic drills available from Tooled-Up.com range from compact, portable units ideal for maintenance work and light fabrication, through to heavy-duty industrial machines capable of drilling holes up to 100mm diameter in thick steel plate. Leading manufacturers including FEIN, Rotabroach, Makita, DeWalt, and Milwaukee offer both corded mains-powered models and increasingly popular cordless battery-operated versions, giving metalworkers unprecedented flexibility on site and in the workshop.

Jargon Buster

• Annular Cutter – A specialist cutting tool with a hollow core that removes only the outer ring of material, leaving a solid slug. More efficient than twist drills for larger holes, producing less waste and requiring less power.
• Magnetic Adhesion Force – Measured in kilograms or Newtons, this indicates the holding strength of the electromagnetic base. Higher values mean greater stability and the ability to work safely on vertical or overhead surfaces.
• Maximum Drilling Capacity – The largest diameter hole the machine can drill, typically specified separately for annular cutters (often 35-65mm) and twist drills (usually 13-16mm).
• Arbor/Weldon Shank – The mounting system for annular cutters, typically featuring a 19mm or 32mm diameter shaft with a flat side and grub screw fixing. Different arbor sizes accommodate different cutter capacities.
• Automatic Feed – An advanced feature where the drill automatically advances at a consistent rate, improving hole quality and reducing operator fatigue on larger machines.
• Safety Strap Point – A reinforced attachment point for securing the machine with a chain or strap as a backup safety measure in case of power failure or magnetic base disengagement.

Who Uses Magnetic Drills?

Magnetic drilling machines are essential tools for a wide range of metalworking professionals and industries:

• Structural Steel Erectors – drilling connection holes in beams, columns, and structural frameworks on construction sites
• Fabricators and Welders – preparing components and assemblies in workshops and on-site installations
• Mechanical Engineers and Fitters – maintenance work on industrial machinery, tanks, and processing equipment
• Railway Infrastructure Workers – drilling rail tracks and associated metalwork for repairs and installations
• Shipbuilders and Marine Engineers – working on hulls, decks, and marine structures
• HVAC Installers – fixing ducting, pipework, and equipment to metal substrates
• Plant and Machinery Maintenance Teams – on-site repairs requiring precise hole placement in heavy equipment
• Automotive and Vehicle Modification Specialists – drilling chassis rails, roll cages, and structural components
• Oil and Gas Industry Workers – drilling pipelines, storage tanks, and offshore structures
• Metal Roofing and Cladding Contractors – installation work on commercial and industrial buildings

How to Choose the Right Magnetic Drills

Power Source: Corded 240v models offer unlimited runtime and consistent power for workshop use and sites with mains electricity. Cordless 18v, 36v, or 40v battery-powered machines provide exceptional portability for site work, working at height, and locations without power access. Consider whether you need the flexibility of cordless operation or the sustained power of mains electricity.

Drilling Capacity: Match the machine's maximum drilling capacity to your typical applications. Compact models handling up to 35mm annular cutters suit general maintenance and light fabrication. Mid-range machines (35-50mm capacity) cover most structural steelwork requirements. Heavy-duty industrial models (50-100mm+) are necessary for large-diameter holes in thick plate and structural sections.

Magnetic Base Strength: Higher adhesion force means greater stability and safety, particularly for vertical or overhead drilling. Look for at least 10,000N for general use, with 15,000N+ for demanding applications. Some FEIN models feature MAGFORCE technology for enhanced holding power with lower power consumption.

Weight and Portability: If you're regularly moving between locations or working at height, lighter compact models (10-15kg) offer significant advantages. Workshop-based users may prefer heavier machines (20-35kg) that provide greater stability and higher drilling capacities.

Feed Mechanism: Manual rack-and-pinion feed systems are reliable and give tactile feedback, ideal for most applications. Automatic feed systems reduce operator fatigue on larger machines and improve hole quality by maintaining consistent feed rates. Some premium models offer variable speed automatic feed for different materials and cutter sizes.

Motor Power: Measured in watts for corded models, this indicates drilling capability. Entry-level machines start around 1,000W, whilst industrial models reach 2,500W+. Brushless motors in cordless models offer improved efficiency, longer runtime, and extended service life compared to brushed alternatives.

Additional Features: Consider coolant systems for continuous heavy-duty work, integrated lighting for poorly-lit locations, quick-change arbors for faster cutter changes, and digital displays showing drilling depth or battery status. The Tooled-Up range includes specialised variants such as FEIN ECO models for cost-effectiveness, ENDURANCE ranges for demanding applications, and UNIVERSAL machines accepting both metric and imperial cutters.

Popular Accessories

• Annular Cutters – available in various diameters and depths, with HSS construction for general steel or TCT (tungsten carbide tipped) for stainless steel and harder materials
• Arbors and Adaptors – enable different cutter sizes and shank types to be used, including metric to imperial conversions
• Standard Drill Chucks – convert the machine to accept conventional twist drills for pilot holes and smaller diameter drilling
• Centre Punches and Pilot Pins – ensure accurate hole positioning and prevent cutter wander when starting holes
• Coolant Systems and Cutting Fluid – extend cutter life, improve hole quality, and remove swarf during drilling operations
• Safety Chains and Straps – essential backup safety equipment to prevent machine falls if magnetic adhesion fails
• Carrying Cases – protect your investment during transport and provide organised storage for cutters and accessories
• Replacement Batteries and Chargers – for cordless models, additional battery packs ensure continuous operation on site
• Swarf Brushes and Cleaning Tools – maintain the magnetic base contact surface for optimal adhesion

Safety Information

Magnetic drilling machines require careful attention to safety due to their unique operating characteristics. Always refer to the HSE guidelines for working with portable power tools and the manufacturer's specific instructions.

Securing the Machine: Never rely solely on the magnetic base. Always use the safety chain or strap to secure the drill to the workpiece before starting operations. If power is interrupted or lost, the electromagnet will disengage immediately, potentially causing the machine to fall. This is particularly critical when working on vertical surfaces or overhead.

Surface Preparation: Ensure the metal surface is clean, flat, and free from paint, rust, scale, or oil before attaching the magnetic base. Contamination significantly reduces adhesion force and can lead to dangerous slippage. The material must be ferrous (magnetic) steel with sufficient thickness – generally at least 12mm for safe operation.

Electrical Safety: Magnetic drills operate at 240v mains voltage or use high-capacity batteries. Never use these tools in wet conditions or around water due to serious electric shock risk. Regularly inspect power cables for damage, and use RCD protection (residual current device) when working on construction sites as required by current UK building regulations.

Personal Protective Equipment: Always wear safety glasses or a face shield as metal swarf can be ejected at high speed. Use hearing protection during extended operations. Wear appropriate gloves when handling sharp annular cutters, but remove gloves during actual drilling operations to prevent entanglement hazards. Steel toe-capped boots provide protection should the machine or workpiece fall.

Cutter Handling: Annular cutters and drill bits become extremely hot during use. Allow adequate cooling time before handling, or use appropriate tools. Ensure cutters are properly secured in the arbor with grub screws tightened correctly – a loose cutter can be ejected with considerable force.

Work Area Management: Maintain good housekeeping around the drilling area. Metal swarf is sharp and creates slip hazards. When drilling through material, be aware of what lies beyond the workpiece to avoid damage to hidden services or injury from the emerging cutter.

Frequently Asked Questions

Can I use a magnetic drill on stainless steel or aluminium?

Magnetic drills can drill through stainless steel and other non-ferrous metals, but the magnetic base must be attached to a ferrous (magnetic) steel backing surface. The material being drilled doesn't need to be magnetic, but the surface the base adheres to must be. For drilling aluminium or stainless steel, use the appropriate TCT annular cutters designed for these harder materials.

What's the difference between an annular cutter and a standard drill bit?

An annular cutter is hollow and removes only the outer ring of material, leaving a solid slug in the centre. This design requires significantly less power, drills faster, produces less waste heat, and creates more accurate holes than conventional twist drills, especially in larger diameters. For holes above 13mm in metal, annular cutters are far more efficient. Most magnetic drills can also accept standard drill bits via an interchangeable chuck for smaller holes.

How thick does the metal need to be for the magnetic base to work safely?

Generally, the steel workpiece should be at least 12mm thick for adequate magnetic adhesion, though this varies by machine and application. Thinner materials may not provide sufficient magnetic force for safe operation. Always check the manufacturer's specifications for minimum material thickness, and when working on thinner materials, consider using a thick steel backing plate for the magnetic base to adhere to.

Are cordless magnetic drills as powerful as corded models?

Modern cordless magnetic drills using 36v or 40v battery technology, such as the DeWalt XR and Makita XGT ranges, offer impressive performance that rivals corded models for most applications. They're ideal for site work, working at height, and locations without mains power. However, corded 240v machines still provide advantages for sustained heavy-duty drilling in workshop environments where unlimited runtime and consistent maximum power are required.

Do I need to use cutting fluid when drilling with a magnetic drill?

Using appropriate cutting fluid or coolant significantly extends annular cutter life, improves hole quality, and makes drilling easier by reducing friction and heat. Whilst not strictly essential for occasional use in thin materials, cutting fluid is highly recommended for production work, drilling stainless steel or hardened materials, and when using larger diameter cutters. Many magnetic drills at Tooled-Up.com include integrated coolant systems or coolant bottles for convenient application during operation.