Flap Discs

Flap discs are abrasive accessories used in commercial metalworking, fabrication, maintenance, and shop environments for grinding, material removal, weld blending, surface preparation, and finishing. The selection includes Type 27 and Type 29 flap-disc profiles, along with resin fiber discs for compatible equipment, in abrasive materials and grit levels suited to different stages of metal finishing.

Product Display:
Helpful Buying Guide

Choose flap discs for the work, surface, and equipment you use

Compare disc profile, abrasive material, grit, diameter, and mounting style before choosing. The products represented here support work on ferrous and non-ferrous metals, including applications such as weld grinding, edge and seam blending, finishing flat surfaces, and working on contoured pieces.

Visual Guide

Popular examples in this category

Aluminum Oxide Resin Fiber Sanding Disc, 4-1/2 in. x 7/8 in., 60 Grit, 3-PackAluminum Oxide Resin Fiber Sanding Disc, 4-1/2 in. x 7/8 in., 60 Grit, 3-PackWBB2139754Type 27 Zirconia Flap Disc, 4-1/2 in. x 7/8 in., 60 GritType 27 Zirconia Flap Disc, 4-1/2 in. x 7/8 in., 60 GritWBB1036812Type 27 Zirconia Flap Disc, 4-1/2 in. x 5/8 in., 40 GritType 27 Zirconia Flap Disc, 4-1/2 in. x 5/8 in., 40 GritWBB21395965 in. Resin Fiber Disc, 7/8 in. Arbor, 80 Grit Aluminum Oxide5 in. Resin Fiber Disc, 7/8 in. Arbor, 80 Grit Aluminum OxideWBB2139569
Use Cases

Match the disc to the finishing task

Use coarser 24-, 36-, or 40-grit options for aggressive or cutting-focused work, including heavy-duty abrasive tasks, surface preparation, and weld grinding. Choose 60- or 80-grit discs for material removal and finishing, while 150 grit supports controlled blending and finishing.

How to Choose

Confirm profile, grit, and fit

Select Type 27 discs for flat work areas, outside corners, and finish grinding, or Type 29 discs for angled or flat grinding and blending. Then confirm the disc diameter, arbor opening, or 5/8-11 threaded hub matches compatible equipment.

Applications

Support common metalworking processes

Representative products are intended for metal sanding, grinding, deburring, seam and edge work, weld blending, stock removal, surface preparation, and finishing. Some options are identified for ferrous and non-ferrous metals, and loading resistance is noted for aluminum work on one 80-grit zirconium disc.

Additional Info

Consider abrasive and backing construction

Available abrasive types include aluminum oxide, zirconia or zirconium, and ceramic. Product constructions include resin fiber discs and flap discs with fiberglass, cotton, polyester-cotton, polyester, plastic, or hard plastic backing; some high-density flap designs are described for longer abrasive life.

24–150Grit range represented

Options range from 24-grit aluminum oxide to 150-grit grind-and-finish construction.

Type 27 & 29Disc profiles

The selection includes flat-face Type 27 and angled or flat-grinding Type 29 designs.

4-1/2–5-1/2 in.Disc diameters

Representative disc sizes span 4-1/2 inch, 5 inch, and 5-1/2 inch formats.

3 mount stylesFit options represented

Products use 7/8-inch arbor openings, 5/8-inch arbor openings, or 5/8-11 threaded hubs.

Comparison Guide

Compare the abrasive disc types represented

Use this overview to distinguish between the flap-disc profiles and resin fiber disc options in the selection.

Product typeWhat it is represented to supportKey selection details
Type 27 flap discsFinish grinding, flat work areas, outside corners, material removal, and high-pressure work on select high-density models.Available in 36, 40, 60, and 80 grit examples; check diameter, arbor opening, or 5/8-11 threaded hub.
Type 29 flap discsFlat grinding, weld grinding, surface preparation, blending, and finishing contoured workpieces.Available in 40, 60, and 150 grit examples; choose zirconium, ceramic, or combined coated and non-woven abrasive construction as represented.
Resin fiber discsMetal sanding, blending, and finishing work on compatible equipment.Available in aluminum oxide with 24, 60, and 80 grit examples; confirm 4-1/2- or 5-inch diameter and 7/8-inch opening.
Planning Guide

Plan the right fit before choosing

Start with the job

Choose grit for the level of removal or finish needed

Grit is a primary selection point across this range. Lower grit numbers represented in the selection are intended for more aggressive work, while higher grit options support more controlled finishing and blending.

  • 24 grit: a specified aluminum oxide option for finishing-process selection.
  • 36 grit: an aggressive zirconium surface for heavy-duty work.
  • 40 grit: available in zirconia, zirconium, and ceramic for grinding, surface preparation, weld work, and cutting-focused finishing.
  • 60 and 80 grit: represented for material removal, general-purpose finishing, and metal sanding.
  • 150 grit: supports controlled blending and finishing on contoured workpieces.
Select the disc profile

Use Type 27 or Type 29 based on the workpiece and grinding approach

Type 27 products have a flat-face format represented for finish grinding on flat surfaces and outside corners; one Type 27 product specifies a 5 to 15 degree grinding angle. Type 29 products are represented with angled or flat-grinding profiles and include options for blending and finishing contoured workpieces.

  • Type 27: represented for flat work areas, outside corners, high-pressure work, and general finishing.
  • Type 29: represented for flat grinding, surface preparation, weld grinding, and blending contoured pieces.
  • One Type 29 grind-and-finish disc combines coated and non-woven abrasives to combine grinding and finishing work in one disc.
Verify equipment compatibility

Check diameter and mounting before ordering

Disc sizes in the selection include 4-1/2 inch, 5 inch, and 5-1/2 inch formats. Mounting options include 7/8-inch and 5/8-inch arbor openings as well as 5/8-11 threaded hubs.

  • 4-1/2-inch discs are represented with 7/8-inch and 5/8-inch center openings.
  • 5-inch options include 7/8-inch arbor openings and 5/8-11 threaded hubs.
  • A 5-1/2-inch, 36-grit Type 27 disc is represented with a 5/8-11 threaded hub.
  • Confirm both disc diameter and the required arbor opening or threaded connection with compatible equipment.
FAQ

Common questions before buying

What is the difference between Type 27 and Type 29 flap discs?

Type 27 discs are represented for flat work areas, outside corners, and finish grinding. Type 29 discs are represented for angled or flat grinding, blending, and work on contoured pieces.

Which grit should I choose?

The selection ranges from 24 to 150 grit. Products with 24, 36, and 40 grit are represented for more aggressive, grinding, preparation, or cutting-focused work, while 60, 80, and 150 grit options support material removal, finishing, blending, or controlled finishing.

What mounting sizes are available?

Representative products include 7/8-inch and 5/8-inch arbor openings, plus 5/8-11 threaded hubs. Disc diameters include 4-1/2 inch, 5 inch, and 5-1/2 inch.

Are these discs suitable for aluminum?

Several products are identified for ferrous and non-ferrous metals. One 80-grit Type 27 zirconium flap disc specifically notes loading resistance when working on aluminum.

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