Grinder Cup Brushes

About Grinder Cup Brushes

Grinder cup brushes are rotary wire brushes designed to attach securely to angle grinders via an M14 threaded connector, providing powerful surface preparation and cleaning capabilities for metalwork applications. Available in diameters from 65mm to 100mm, these essential accessories suit most 115mm and 125mm angle grinders commonly used across UK construction sites and workshops. MyToolShed.co.uk stocks over 40 grinder cup brushes from trusted manufacturers including Bosch Professional, Lessmann, Faithfull, Draper, and Sealey.

The range encompasses various wire configurations to suit different tasks—crimped wire brushes offer flexible, controlled cleaning for lighter applications and working into recesses, whilst twisted knot brushes deliver aggressive material removal for heavy-duty descaling and rust removal. Wire materials include standard carbon steel for general metalwork, inox (stainless steel) wire for working on stainless steel without contamination, and brass wire for softer metals and aluminium. Modern innovations like Bosch's X-Lock system enable tool-free brush changes, significantly reducing downtime on busy sites.

Applications

Grinder cup brushes are indispensable tools for tradespeople and industries requiring metal surface preparation and cleaning:

• Welders and Fabricators: Removing mill scale, cleaning welds, and preparing metal surfaces before and after welding operations
• Steel Erectors: Cleaning structural steelwork, removing corrosion from girders and beams
• Automotive Mechanics: Paint stripping, rust removal, cleaning engine components and chassis parts
• Maintenance Engineers: General metal cleaning, removing corrosion from machinery, refurbishing industrial equipment
• Shipyard Workers: Heavy-duty descaling and rust removal from marine metalwork
• Plant Fitters: Cleaning farm machinery, removing paint and corrosion from agricultural implements
• Metal Restoration Specialists: Preparing ironwork, gates, railings, and architectural metalwork for refinishing
• DIY Enthusiasts: Home restoration projects, garden furniture renovation, general metalwork cleaning

Choosing The Right Grinder Cup Brushes

Wire Type: Select crimped wire for lighter cleaning and surface finishing, or twisted knot brushes for aggressive rust removal and heavy scale. Always use inox wire brushes on stainless steel to prevent contamination, and brass wire for softer metals and aluminium.

Wire Gauge: Finer gauges (0.3mm) provide gentler cleaning for delicate surfaces, medium gauges (0.5mm) offer versatile general-purpose cleaning, whilst thicker gauges (0.8mm) deliver maximum aggression for heavy industrial applications.

Brush Diameter: Match the brush size to your grinder—65mm to 75mm brushes suit 115mm grinders, whilst 100mm brushes work best with 125mm grinders. Verify M14 threading compatibility with your grinder's spindle.

Speed Rating: Always check the maximum RPM rating matches or exceeds your grinder's operating speed (typically 10,000-12,000 RPM). Running brushes above their rated speed risks wire breakage and serious injury.

Brand Quality: Premium brands like Bosch Professional and Lessmann available at MyToolShed.co.uk use higher quality wire that resists breakage and maintains performance longer, justifying the investment for professional daily use.

Safety Information

Wire bristles can detach during operation and become dangerous projectiles. Always wear full face protection and heavy-duty gloves, ensuring all exposed skin is covered. Never exceed the maximum RPM rating stamped on the brush hub—check this against your grinder's specification before use. Inspect brushes before mounting for damage or loose wires, discarding any compromised brushes immediately.

Ensure your grinder's guard is correctly positioned and work in well-ventilated areas or use dust extraction, as wire brushing generates fine metal particles presenting inhalation hazards. Allow new brushes to run at operating speed for one minute whilst pointing at the ground before beginning work, allowing any loose wires to detach safely. Maintain a firm two-handed grip and ensure workpieces are securely clamped.

Frequently Asked Questions

Can I use a standard steel wire brush on stainless steel?

No, never use standard carbon steel wire brushes on stainless steel surfaces. The carbon steel particles embed into the stainless steel causing rust spots and contamination. Always use inox (stainless steel) wire brushes specifically designed for stainless steel work to maintain the material's corrosion resistance and appearance.

What size cup brush do I need for my angle grinder?

Match the brush diameter to your grinder size—65mm to 75mm brushes suit 115mm (4.5") angle grinders, whilst 100mm brushes work best with 125mm (5") grinders. Verify M14 threading is compatible with your grinder's spindle. The brush diameter should be smaller than your grinder's disc capacity to ensure proper clearance and safe operation.

What's the difference between crimped and twisted knot wire brushes?

Crimped wire brushes have individual wires that are waved to create flexibility, making them less aggressive and suitable for lighter cleaning tasks without excessive material removal. Twisted knot brushes bunch thick gauge wires together in tight knots for maximum aggression, removing material quickly—ideal for heavy-duty descaling and rust removal, though they will scratch softer metals.