Flap Discs

Flap Disc Selection — Quick Reference

Flap discs combine GRINDING + SANDING in one disc — overlapping abrasive flaps wear down gradually exposing fresh grain. Used on angle grinders for weld blending + edge prep + surface conditioning. Selection by abrasive + grit + backing + shape.

Critical: Match abrasive to material — Zirconia/Ceramic on STAINLESS (carbon-steel abrasives contaminate SS surface). Match disc MAX RPM to angle grinder spec — 115mm typically 13,300 RPM max, 125mm 12,200 RPM max. Use angle: 5-15° from horizontal — too flat = full-face contact (poor cut + loads grain); too steep = aggressive removal + heavy material loss. Brands: Pferd, Klingspor, Norton, Flexovit. Companion: all abrasives, grinding wheels, sanding belts.

Flap Discs

AIMS Industrial stocks flap discs from Pferd, Klingspor, Flexovit, Bordo, Norton and Rocket — a complete range covering flat, conical and curved profiles in aluminium oxide, zirconia alumina, ceramic and non-woven abrasive grains. Disc sizes of 100mm, 115mm and 125mm suit standard angle grinders, with grits from 40 through to 120 for coarse stock removal through to fine surface blending.

The range serves fabricators, welders, maintenance tradespeople and metalworking shops working on steel, stainless steel, aluminium and non-ferrous metals. Whether the job is grinding weld seams, prepping surfaces for paint or blending stainless steel to a uniform finish, AIMS stocks a flap disc engineered for the task.

Types of Flap Disc

• Flat (Type 27 / 0°): Low-profile disc for flat surface grinding and blending. Consistent full-face contact on flat workpieces; suited to surface prep, deburring and general grinding.
• Conical (Type 29 / 12°): Angled profile for more aggressive cutting action and better access to weld seams, pipe and curved surfaces. Higher stock removal rate than flat profile.
• Curved (SGP Profile): Pferd’s patented Polifan SGP geometry, optimised for peripheral grinding with higher chip clearance. Cool cutting action on stainless steel, inox and heat-sensitive alloys.
• Non-Woven / Finishing: Open-mesh abrasive construction for surface conditioning, blending and final finishing without aggressive material removal. Available in Klingspor SMT800, SMT850 and MFW600 series.

Abrasive Grain Types

• Aluminium Oxide: General purpose grain for steel and non-ferrous metals. Good performance-to-durability ratio for maintenance, fabrication and general grinding tasks.
• Zirconia Alumina: Harder, tougher grain that self-sharpens under pressure for extended service life on steel and stainless steel. Preferred for production grinding where disc life matters.
• Ceramic (SG/SGP): Pferd’s SGP series and Norton’s Blaze range use engineered ceramic grain. Self-sharpening under high load, cool-cutting and long-lasting. Best for heavy stock removal on stainless steel and specialty alloys.
• Silicon Carbide / Non-Woven: Klingspor MFW600 and SMT series non-woven flap discs for precision surface conditioning and pre-polish blending, particularly on stainless steel sheet and tube.

Brand Guide

• Pferd Polifan: 17 products spanning flat GP, curved SGP and conical profiles across ceramic, zirconia and aluminium oxide grains. Highlights include the SGP Ceramic Steel/Inox Curve, SGP Zirconia Curve, Conical Premium Zirconia Power, Flat Premium Al Oxide Steel/Inox and finishing options including the Felt Flap Disc and Combidisc Felt disc. Widely specified in fabrication and manufacturing for consistent finish and long service life.
• Klingspor: five SMT and MFW-series discs engineered for stainless steel applications. Includes SMT626 Zirconia 6°, SMT624 Zirconia 12°, SMT800 Non-Woven 12°, SMT850 Non-Woven 12° and MFW600 Silicon Carbide Non-Woven. Ideal for surface conditioning and fine finishing on stainless steel tube and sheet.
• Flexovit: four Mega-Line Blue HD R860 series discs built for industrial grinding performance. Includes R860 125 × 22mm 80 Grit, R860 115 × 22mm 40 Grit and AC-ZEC Silicon Carbide Flap Disc. Designed for consistent, aggressive cut in production environments.
• Bordo: two zirconia flap disc options for structural steel and general fabrication — Bordo Zirconia Flap Disc and a convenient Clamshell Pack variant. A practical choice for tradespeople in workshop and on-site environments.
• Norton: two products covering premium cutting and surface finishing. Norton Blaze Orange Aluminium Oxide Flap Disc for aggressive stock removal, and Bear-Tex Rapid Blend Type 29 for blending and finishing on stainless steel.
• Rocket: the Rocket Flap Disc for Angle Grinders is an economy option suited to light to medium steel grinding in trade and maintenance environments.

Typical Applications

• Weld seam grinding, blending and smoothing on fabricated steel structures
• Surface preparation before painting, powder coating or galvanising
• Rust, mill scale and heat tint removal from structural and sheet steel
• Deburring and edge dressing on laser-cut, plasma-cut and punched parts
• Stainless steel finish blending, polishing and scratch removal
• Aluminium surface finishing and oxide layer removal
• Pipe, tube and curved surface grinding using conical or SGP profile discs

Expert Support: Contact our team if you need help selecting the right product for your application, or request a quote.

Australian Business, Local Supply: AIMS Industrial has supplied Australian tradespeople and industry since 1988.

Also see our Abrasives, Wire Brushes and Sanding Discs ranges.

People Also Ask — Flap Discs

Q: What's the difference between a T27 flat and T29 conical flap disc?

T27 (flat, 0°) is a low-profile disc for flat surface grinding and blending, giving consistent full-face contact on flat workpieces — suited to surface prep, deburring and general grinding. T29 (conical, 12°) has an angled profile for more aggressive cutting action and better access to weld seams, pipe and curved surfaces, with a higher stock removal rate than the flat profile.

Q: Why can't I use a standard flap disc on stainless steel?

Carbon-steel abrasive grains (aluminium oxide) can contaminate a stainless surface. Use zirconia alumina or ceramic grain flap discs on stainless instead — aluminium oxide is the general workshop choice for steel and mild steel, not stainless.

Q: What angle should I hold a flap disc at?

5-15° from horizontal. Too flat gives full-face contact, which cuts poorly and loads the grain; too steep gives overly aggressive removal and heavy material loss.

Q: What's the max RPM for 115mm vs 125mm flap discs?

115mm discs are typically rated to 13,300 RPM max, and 125mm discs to 12,200 RPM max. Always match the disc's rated max RPM to your angle grinder's spec — never exceed it.

Q: What's a non-woven flap disc used for?

Non-woven flap discs (open-mesh abrasive construction, such as Klingspor's SMT800, SMT850 and MFW600 series) are for surface conditioning, blending and final finishing without aggressive material removal — suited to pre-polish blending on stainless steel sheet and tube.