Grinders

About Grinders

Grinders are amongst the most versatile and essential power tools in any professional workshop, construction site, or home garage. These robust machines utilise high-speed rotating abrasive wheels or discs to perform a remarkable range of tasks including cutting through metal and masonry, grinding down welds, removing rust and paint, sharpening tools, and polishing surfaces to a professional finish. From preparing steel fabrications in industrial settings to cutting paving slabs for landscaping projects, grinders have become indispensable across virtually every trade and countless DIY applications throughout the UK.

The grinder category encompasses several distinct tool types, each engineered for specific applications. Angle grinders represent the most popular and versatile option, offering exceptional manoeuvrability for both cutting and surface grinding tasks. Bench grinders provide a stable workshop solution for sharpening cutting tools and finishing metalwork components. Cordless grinders deliver unmatched mobility for site work where mains power isn't readily accessible. Die grinders excel at precision work in confined spaces, whilst straight grinders are purpose-built for heavy-duty material removal in industrial environments. Tooled-Up.com stocks professional-grade models from leading manufacturers including Makita, DeWalt, Milwaukee, Bosch, and Fein—all engineered to withstand demanding daily use whilst meeting stringent UK and BS EN safety standards.

Modern grinder technology has advanced considerably in recent years. Brushless motor designs now offer superior efficiency and extended service life compared to traditional brushed motors. Cordless models equipped with high-capacity lithium-ion batteries can deliver performance rivalling corded 240v equivalents, providing professionals with genuine alternatives for site-based applications. Electronic innovations such as soft-start functionality, variable speed control, and sophisticated anti-vibration systems have significantly improved operator comfort and safety during extended use—critical considerations given HSE guidelines on hand-arm vibration syndrome prevention for professional users.

Jargon Buster

• Disc Diameter: The size of the grinding or cutting wheel, typically measured in millimetres. Common angle grinder sizes include 115mm, 125mm, and 230mm. Larger discs provide deeper cuts and faster material removal but require more powerful motors and result in heavier, more demanding tools to control safely.
• No-Load Speed (RPM): The rotational speed of the spindle measured in revolutions per minute when the tool operates without resistance. Angle grinders typically run between 8,000-12,000 RPM, whilst bench grinders operate at 2,850-3,450 RPM. Always ensure discs are rated above your grinder's maximum RPM.
• Spindle Thread: The threaded shaft onto which grinding discs and accessories mount. M14 threading is standard for angle grinders in the UK, whilst die grinders use specific collet sizes. Compatibility between disc bore sizes and spindle fittings is essential for safe operation.
• Dead Man's Switch: A crucial safety feature requiring constant operator pressure to maintain tool operation. Releasing the trigger immediately stops the grinder—preventing continued operation if the tool is dropped or control is lost during kickback incidents.
• Brushless Motor: Advanced motor technology eliminating carbon brushes, resulting in superior efficiency, extended battery runtime on cordless models, reduced maintenance requirements, and significantly longer service life compared to traditional brushed motor designs.
• Soft Start: Electronic feature that gradually increases motor speed during startup rather than reaching full speed instantly. This reduces sudden torque that could cause the tool to kick or twist in your hands, whilst also minimising electrical stress on circuits and tripping issues.

Who Uses Grinders?

Grinders are essential tools across numerous trades and applications throughout the UK:

• Welders and Fabricators: Preparing joints before welding, grinding down weld seams flush, cutting metal stock to length, and achieving professional finishing on metalwork projects
• Construction Workers and General Builders: Cutting concrete blocks, paving slabs, bricks, and stone on site, plus removing mortar and preparing surfaces
• Metalworkers and Engineering Professionals: Precision grinding, deburring sharp edges, shaping metal components, and finishing machined parts in workshops and manufacturing facilities
• Plumbers and Heating Engineers: Cutting through various pipework materials, removing corroded or seized fixtures, and preparing surfaces for welding or soldering applications
• Automotive Technicians and Body Shop Specialists: Removing paint, rust, and corrosion from vehicle panels, cutting structural components, grinding welds, and preparing surfaces for refinishing
• Stonemasons and Tiling Contractors: Cutting and shaping natural stone, porcelain tiles, ceramic materials, and masonry products for installation projects
• Tool and Die Makers: Sharpening cutting tools, drill bits, chisels, and maintaining workshop equipment using bench grinders with appropriate grinding wheels
• Groundworkers and Landscapers: Cutting paving materials, concrete products, and natural stone for pathways, patios, and landscaping features
• DIY Enthusiasts and Home Improvers: Tackling various cutting, grinding, rust removal, and finishing tasks around the property

How to Choose the Right Grinders

Type of Grinder: Consider your primary applications carefully. Angle grinders offer maximum versatility for both cutting and grinding across metal and masonry materials. Bench grinders suit workshop environments where you need a permanent station for sharpening tools and finishing components. Cordless models provide unmatched mobility for site-based work without access to mains power. Die grinders and straight grinders serve specialised industrial applications requiring precision or heavy-duty performance.

Disc Size for Angle Grinders: The 115mm models available at Tooled-Up offer excellent manoeuvrability and sufficient capability for most light to medium-duty tasks. These are ideal for DIY users and tradespeople requiring portable cutting and grinding. The 125mm size provides a balanced combination of power and control for general professional applications. Larger 230mm grinders deliver maximum cutting depth (up to 65mm) for structural steel work but are considerably heavier and demand greater experience to control safely.

Power Source Considerations: Corded 240v grinders deliver consistent, uninterrupted power for extended heavy-duty applications and are ideal for workshop environments with accessible electrical outlets. Cordless grinders using 18V or higher voltage battery platforms provide freedom of movement on construction sites and eliminate cable trip hazards, though they require battery management and may offer slightly reduced power for the most demanding materials. If you already invest in a particular battery ecosystem (Makita LXT, DeWalt XR, Milwaukee M18), choosing a compatible grinder maximises your existing battery investment.

Motor Power: For corded angle grinders, look for 500-900W motors on 115mm models and 2,000-2,500W on 230mm grinders. Higher wattage provides more power for demanding materials like stainless steel and reinforced concrete but increases tool weight. Cordless models should ideally use high-capacity batteries (5.0Ah minimum) for acceptable runtime on typical applications.

Safety Features: Prioritise tools incorporating anti-restart protection (preventing automatic startup after power interruption), dead man's switches, tool-free adjustable guards, and soft-start functionality. Vibration reduction systems are particularly important for protecting against hand-arm vibration syndrome (HAVS) during prolonged use—a serious occupational health consideration under HSE guidelines for professional users.

Brand and Build Quality: Professional-grade brands like Makita, DeWalt, Milwaukee, and Bosch offer superior durability, comprehensive UK warranties, readily available spare parts, and service networks. For occasional DIY applications, brands like Einhell provide good value whilst maintaining adequate safety standards and performance for lighter-duty use.

Popular Accessories

• Grinding Discs: Depressed centre discs for general metalwork, flap discs for surface finishing and blending, and diamond grinding wheels for concrete and stone preparation
• Cutting Discs: Thin metal cutting discs (1mm-3mm thickness) for steel, stainless steel, aluminium, and specialist masonry cutting discs for concrete, stone, and brick
• Diamond Blades: Segmented, continuous rim, and turbo designs for cutting various masonry materials, tiles, and stone products
• Wire Brushes: Cup brushes and wheel brushes for removing rust, paint, scale, and corrosion from metal surfaces
• Polishing Attachments: Backing pads, polishing bonnets, buffing wheels, and polishing compounds for achieving professional finishes on metalwork and stone
• Safety Equipment: Face shields, safety goggles meeting BS EN standards, hearing protection, dust masks rated FFP2 or FFP3 for harmful dust, and protective gloves rated for grinding operations
• Grinding Guards: Replacement guards and specialist dust extraction hoods for compliance with COSHH regulations when cutting materials producing harmful dust
• Spare Flanges and Spanners: Essential components for secure disc mounting and routine maintenance
• Carry Cases and Storage: Protective carrying cases, many compatible with modular storage systems like DeWalt TSTAK, Milwaukee PACKOUT, and Makita MakPac
• Replacement Carbon Brushes: Service parts for maintaining brushed motor grinders and extending their operational lifespan

Safety Information

Grinders are powerful tools that demand respect and proper safety practices at all times. Always wear appropriate personal protective equipment including safety goggles or preferably a full face shield, hearing protection rated for high noise levels, and dust masks rated FFP2 or FFP3 when grinding materials producing harmful dust. Never remove or modify safety guards—they're specifically designed to protect you from disc fragments in the catastrophic event of disc breakage at high speed.

Inspect discs carefully before fitting for any damage, cracks, or chips, and always ensure they're rated for speeds exceeding your grinder's maximum RPM. Never use cutting discs for grinding operations or grinding discs for cutting, as each type is engineered for specific directional stresses. Allow new discs to run at full speed for 30 seconds before applying pressure, and never force the tool—excessive pressure reduces efficiency and increases breakage risk.

Be particularly aware of hand-arm vibration syndrome (HAVS) risks. The HSE provides exposure action and limit values, and professional users must monitor their cumulative vibration exposure, especially when using grinders regularly throughout the working day. Modern grinders equipped with anti-vibration systems significantly reduce these risks. Always disconnect mains power or remove batteries before changing discs or performing any maintenance.

When operating grinders, position yourself to the side of the tool, never directly behind it where kickback could cause injury. Maintain a firm two-handed grip at all times. Secure workpieces properly using clamps or vices—never attempt to hold small pieces by hand whilst grinding. Be mindful of hot sparks and grinding debris, particularly in environments containing flammable materials, dusts, or gases. Ensure adequate ventilation when working indoors to prevent harmful dust accumulation and maintain air quality.

When cutting masonry materials, be aware that dry cutting produces respirable crystalline silica dust—a serious health hazard requiring FFP3-rated respiratory protection and ideally dust extraction or suppression systems to comply with current HSE guidance and COSHH regulations.

Frequently Asked Questions

What's the difference between grinding discs and cutting discs?

Grinding discs are thicker (typically 6mm) with a depressed centre design, engineered to withstand side pressure for grinding, shaping, and surface preparation applications. Cutting discs are much thinner (1-3mm) and must only be used at 90-degree angles to the material being cut—never for side grinding. Using cutting discs for grinding operations will cause them to flex excessively and shatter dangerously. Always check the disc labelling carefully and use the correct type for your specific application to ensure safe operation.

Can I use an angle grinder to cut paving slabs and bricks?

Yes, angle grinders are excellent for cutting masonry materials, but you must fit a diamond cutting disc specifically rated for concrete, stone, or masonry applications. Standard metal cutting discs will be destroyed immediately and may shatter dangerously. For extensive masonry cutting work, consider a grinder with dust extraction capability or water-feed attachment to comply with HSE silica dust regulations, as dry cutting produces harmful respirable crystalline silica dust requiring FFP3-rated respiratory protection and ideally suppression measures.

Do I need a cordless or corded grinder?

Corded 240v grinders provide unlimited runtime and consistent power delivery for workshop-based use and extended heavy-duty applications without battery management concerns. Cordless grinders offer unmatched portability for site work where mains power isn't accessible and eliminate cable trip hazards. If you already use a particular battery platform (Makita, DeWalt, Milwaukee), choosing a compatible cordless grinder maximises your existing battery investment. For professional use involving both workshop and site scenarios, many tradespeople find value in owning both types for different applications.

How often should I replace grinding discs?

Replace discs when they've worn down to approximately 80mm diameter (for 115mm discs) or show any signs of cracking, chipping, damage, or uneven wear patterns. Additionally, discs have expiry dates printed on their labels—typically three years from manufacture date—as the bonding resin degrades over time even when unused. Never use expired discs regardless of their apparent condition, as degraded bonding significantly increases the likelihood of disc disintegration during high-speed operation.

What size angle grinder should I choose?

For general DIY and light trade work, a 115mm grinder offers the best combination of manoeuvrability, control, and capability for most typical cutting and grinding tasks. Professional metalworkers and fabricators often prefer 125mm models for additional power and cutting depth (around 30mm) whilst maintaining good control and reasonable weight. Only choose 230mm grinders if you regularly require maximum cutting depth (up to 65mm) for heavy structural steel work, as they're considerably heavier, more physically demanding to control safely, and require greater experience to operate without incident.