Collection: Flap Discs

Flap Discs for Angle Grinders and Die Grinders

Whether you're grinding welds, deburring sharp edges, or polishing metal to a mirror finish, having the right flap disc is crucial. At salitools, we carry a wide selection of the best flap discs designed for maximum performance, longevity, and superior results. From aggressive material removal to fine surface conditioning, this guide will help you select the perfect grinder flap disc for your grinder and your specific project.

Flap Disc Buyer’s Guide - Step 1 — Determine Abrasive Grain by Material & Task

Application / Material Disc Setup (Grain/Coating)

Grinding or Blending Stainless Steel Ceramic (coolest cut prevents discoloration + has the longest life), Zirconia (value workhorse)

Grinding or Blending Hard + Exotic Aerospace Alloys (Titanium, Nickel, Cobalt Alloys) Ceramic (aggressive grinding on tough metals + best for heat sensitive metals)

Grinding or Blending Hard Metals (carbon/mild steel, cast iron, etc.) Zirconia (durable grain for heavy stock removal and extended use)

Grinding or Blending Aluminum & Soft Non-Ferrous Metals (aluminum, brass, copper, bronze) Ceramic grain + calcium-stearate (cooler cutting with anti-loading /clogging coat)

Finish & Prep (minimal base-metal removal) Surface-Conditioning Flap Discs (controlled finish; great after weld cleanup)

Detail Work & Tight Spaces 2” & 3” Mini Flap Discs (quick-change style)

Final Polish Felt polishing flap disc + polishing compound

Pro Tip: Don't reuse a flap disc on different types of metal. For best results, assign and mark discs per material to prevent contamination, reduce rework, and preserve finishes.

Flap Disc Buyer’s Guide - Step 2 — Determine the Best Flap Disc Setup (Shape / Density)

Shape/Type:

T27 (flat): Best for blending, flat surfaces, finishing

T29 (conical): Best for aggressive grinding, contours/edges

Curved Edge: Best for grinding fillet welds and in tight corners

Density:

Standard: Everyday grinding and blending for quick material removal

XL High Density: (≈50% more flaps) for longer life and smoother grinding

Flap Disc Buyer’s Guide - Step 3 — Pick the Right Grit(s) - Flap Disc Grit Chart

Your Task Best Grit What It Does

Heavy weld removal, beveling, fast rust/paint removal on durable steel 36 / 40 (coarse) Maximum stock removal and fastest cut; expect a rough finish—plan to step down to 60–80 to blend.

Weld grinding & initial blending 40 (36 for very heavy welds) Rapid removal with a workable finish; good first step before 60.

General metalworking: blending, deburring, shaping 60–80 grit Balanced removal and surface quality; removes 40-grit scratches.

Thin-gauge or softer metals, edge cleanup, surface prep 80 Clean finish with minimal scratching/gouging; great before primer.

Final finishing & coating prep 120 Smooth finish ready for paint/powder; removes 80-grit marks.

Pro Tip: For the best results, start with a grit just coarse enough for the task, then move to finer ones. This grit progression process is actually faster, creates a much better finish, and saves you money by making your discs last longer.

Additional Considerations

Disc size & RPM: match grinder (2–3", 4-1/2", 5", 7"); never exceed disc’s max RPM

Hubbed vs standard arbor: hubbed 5/8-11 = faster change-outs.

Stainless Steel: look for “contaminant-free” options.

Coatings: grinding aid for stainless/hard alloys; anti-loading (stearate) for aluminum.

Flap Disc FAQ

Q: What is a flap disc?

A flap disc (aka flapper disc) is an abrasive tool made up of multiple layers of overlapping abrasive “flaps” (like strips of sandpaper) adhered to a central hub in a wheel shape. As the disc is used to grind metal or other surfaces, the top layer of abrasive wears away in a controlled manner. Once the material on the outer layer is used up, that sheet will tear off to expose a fresh layer of abrasives.

Q: What are flap discs used for?

Flap discs are most often used for grinding and deburring metal surfaces, removing paint and rust, stock removal, and smoothing out imperfections. Specialty flap discs can be used for polishing and/or surface conditioning metals as well. Below is a list of uses of flap discs:

Grinding Blending Finishing Deburring Deflashing

Edge Chamfering Stock Removal Paint & Adhesive Prep Shaping Metal and Hard Woods Cleaning Metal

Weld Prep Cleaning Weld Lines & Spatter Blending Welds Fillet Weld Sanding (curved flap discs) Sharpening Tools and Blades

Surface Conditioning (non-woven flap discs) Polishing (felt flap discs) Surface Smoothing Paint & Rust Removal Varnish or Epoxy Removal

Q: What's the difference between Type 27 and Type 29 flap discs?

The “type” of design for flap discs specifies the angle that the abrasive sheets are aligned into the wheel.

T27 (Flat Discs) - Type 27 flap disks are flat. This makes them better for smoothing/blending surfaces as well as flat sanding. Use them at a 0-15° angle.

T29 (Conical Discs) - Type 29 flap discs have their abrasive sheets slightly angled on