Flap Discs

About Flap Discs

Flap discs are versatile abrasive accessories designed for angle grinders, featuring overlapping strips of abrasive material arranged radially around a central hub. This construction allows fresh abrasive to be continuously exposed as outer layers wear away, delivering consistent performance throughout the disc's lifespan. Whether grinding metal, blending welds, removing rust or finishing surfaces, flap discs combine aggressive stock removal with fine surface finishing capabilities that standard grinding discs cannot match.

MyToolShed.co.uk stocks flap discs from leading manufacturers including Bosch Professional, Makita, Faithfull, Draper and Sealey in standard 115mm and 125mm diameters. Available in aluminium oxide for general-purpose work and premium zirconium oxide for demanding metalworking applications, our range includes various grit ratings from coarse 40-grit for heavy material removal through to fine 120-grit for finishing. Many modern options feature Bosch X-LOCK technology for tool-free, quick-change convenience on compatible grinders.

Applications

Flap discs are essential tools across numerous trades and industries:

• Welders and Fabricators: Weld blending, spatter removal, and creating smooth transitions between welded joints
• Metalworkers: Deburring edges, removing surface defects, and preparing metal for coating or painting
• Bodywork Specialists: Panel preparation, rust removal, and smoothing filler before painting
• Construction Workers: Cleaning steel, removing concrete splatter, and preparing structural steelwork
• Maintenance Engineers: Equipment refurbishment, removing corrosion, and surface restoration
• Joiners and Carpenters: Shaping timber, removing old finishes, and aggressive sanding of hardwoods
• DIY Enthusiasts: Home renovation, metalwork projects, and restoration work requiring quality finishes

Choosing The Right Flap Discs

Disc Size: Match the diameter to your angle grinder—115mm for standard grinders and 125mm for larger models. Never fit an oversized disc to your tool.

Abrasive Material: Aluminium oxide suits general metalworking and lighter applications. Zirconium oxide costs more initially but lasts significantly longer on intensive steel grinding and professional metalwork.

Grit Selection: Choose 40-60 grit for heavy stock removal and rust stripping, 80 grit for general-purpose grinding, or 120 grit for fine finishing and preparation before painting.

Disc Profile: Flat (Type 27) discs work best at shallow angles for finishing work. Angled (Type 29) discs provide greater contact area for aggressive stock removal at steeper grinding angles.

Mounting System: Standard centre-hole discs fit most grinders with backing pads. Bosch X-LOCK discs offer tool-free mounting—ideal if you change discs frequently. Some professional discs feature M14 threaded mounts for direct attachment.

Brand Considerations: MyToolShed.co.uk stocks Bosch Professional and Makita for professional-grade performance, whilst Faithfull, Draper and Sealey offer excellent value for general trade use.

Safety Information

Always wear impact-resistant safety glasses or face shield, hearing protection, and appropriate respiratory protection when grinding. Ensure adequate ventilation and be aware of COSHH regulations regarding metal dust exposure. Check every disc before use for damage and never exceed the maximum RPM rating. Allow grinders to reach full speed before contact with workpieces, maintain two-handed control, and ensure guards are properly positioned. Store discs flat in dry conditions and follow HSE guidelines for abrasive wheel use.

Frequently Asked Questions

What's the difference between a flap disc and a grinding disc?

Standard grinding discs are solid abrasive wheels for aggressive stock removal, whilst flap discs feature overlapping abrasive flaps providing combined grinding and finishing capabilities. Flap discs produce smoother results, last longer as fresh abrasive is continuously exposed, generate less vibration, and are safer as they won't shatter.

How long does a flap disc typically last?

Lifespan varies depending on abrasive material, grit rating, and application. Premium zirconium oxide discs can last 3-4 times longer than aluminium oxide versions when working steel. A quality 80-grit zirconium disc might provide 30-60 minutes of continuous use in typical metalworking applications.

What grit should I use for removing rust?

Start with 40 or 60 grit for heavy rust removal, then switch to 80 grit to smooth the surface. For paint-ready finishes, complete with 120 grit. Zirconium oxide discs work particularly well for rust removal as they resist loading and maintain cutting ability longer.