What Grit Flap Disc for Sharpening Mower Blades?

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We recommend a 36 or 40-grit flap disc for sharpening mower blades. This will leave a smoother grind for a subsequent re-sharpening. 

Once the proper angle has been established, it will take a few grinding passes to resharpen the blades. In addition, Type 27 or 29 flap discs can also work equally.

Can you sharpen mower blades with a flap disc?

Yes, you can sharpen your mower blades with a flap disc. If you are proficient with an angle grinder, want to have a more efficient and quicker job or the blades are very dull, you can use a hard disc but it should be used with caution.

Best Flap Disc for Sharpening Mower Blades

1. DEWALT DW8311 4-1/2-Inch by 5/8-Inch- 11 36 Grit Zirconia Angle Grinder Flap Disc

The DEWALT DW8311 features type-29 fiberglass which enables a faster material removal than fiber resin metal sanding discs.

Pros:

  • A user liked the fact that the flap disc is easy to use and long-lasting
  • The DEWALT DW8311 grinds down material very fast.
  • An individual attested that it took a few passes to produce a clean and sharp blade.

Cons

  • It is a bit pricey.

The flap disc is durable and long-lasting. It also offers good value for your money. It enhances remarkable sharpening results and also provides a grinding angle of 20-25 degrees.

Its premium abrasive cloth provides up to 15X’s longer life than fiber resin metal sanding discs. Furthermore, the DW8311 model enhances faster material removal. It comes with a 30-day money-back guarantee.

2. 4.5” x 7/8” Premium High-Density Jumbo Zirconia Type 29 Flap Disc

The Benchmark Abrasives-produced flap disc is suitable for grinding, sanding, blending, and finishing on a wide variety of materials. It is a good choice for metal fabricators and welders. In addition, this flap disc is compatible with angle grinders.

Pros:

  • It offers 50% more grinding material than several standard flap discs.
  • The flap disc  is made in accordance with ANSI safety requirements.
  • It provides increased durability than several flap discs.

Cons

  • A user complained about the disc’s short life span.
  • Only a minimal bead of adhesive was used to adhere the flaps.

The flap disc is made in accordance with ANSI safety requirements. The flap disc enhances increased durability and offers an outstanding value for your money.

3. S SATC Abrasive Wheels & Discs 4- 1/2 Inch Flap Disc 10 PCS, Type #29

The S SATC flap disc provides long service life with industrial-grade premium blue zirconia for strength and durability.

Pros:

  • It is effective for blending, smoothing, grinding and deburring.
  • The S SATC flap disc is built for greater contact on the work surface.
  • It is durable and long-lasting.

Cons

  • Not the best for flat surface work.
  • The discs are thin and fragile

It is effective for blending, smoothing, grinding, and deburring. Each disc measures a 4-1/2-inch diameter with a 7/8-inch arbor size. This makes it compatible with several angle grinders.

The type-29 disc is built for greater contact on the work surface. It is ideal for radius grinding on steel, sheet material, industrial maintenance, welding, and heavy-duty equipment.

4. NEIKO 11142A Zirconia Flap Disc 40 Grit, 10 Pack, 4.5” x 7/8-Inch

The NEIKO 11142A flap disc is built with industrial-grade premium zirconia abrasive for strength, increased durability, and longer disc life. It can hold up to pressure and high temperatures.

Pros:

  • The NEIKO 11142A is effective for radius grinding, weld bending, edges and contours
  • The flap disc can hold up to pressure and high temperatures.
  • The 40-grit flap disc absorbs vibrations without smearing the workpiece during usage.
  • It is perfect for heavier stock removal.

Cons

  • Not long-lasting.
  • The flap disc clogs faster

This flap disc is made of a coarse 40 grit zirconia alumina which makes them perfect for aggressive grinding on hard materials like metal.

It is also effective for radius grinding, weld bending, edges, and contours. It has a measurement of 4- 1/2-inch diameter with a 7/8-inch arbor size, making it compatible with grinders with a speed up to 13,300 RPM.

5. Neiko 11255A High-Density Jumbo Premium Zirconia Flap Disc, 40 Grit

The 40-grit flap disc is coarser in build and perfect for heavier stock removal. It has a resin fiber construction with a fiberglass backing plate for absorption of vibrations during usage.

Pros:

  • The Neiko 11255A flap disc can easily absorb vibrations during usage.
  • It is ideal for heavier stock removal.
  • It is durable and long-lasting.

Cons

  • A user complained that they wear out on a standard angle grinder.
  • The flap disc loses its abrasive material in a fast manner.

Each disc measures at 4- ½-inch diameter with a 7/8-inch arbor size to make it compatible with grinders that operate up to 13,300 RPM.

The Neiko 11255A flap disc offers increased durability and longevity. It is also made up of industrial-grade high-density premium zirconia to provide more grinding material than several standard flap discs.

6. KSEIBI Aluminum Oxide Auto Body Flap Disc Sanding Wheel

The KSEIBI Aluminum Oxide Flap disc offers a wide range of tasks such as grinding, cleaning, and stock removal. Apart from steel, you can use this flap disc on rust and paint. It also does a good job on non-ferrous metals.

Pros:

  • The KSEIBI flap disc provides an aggressive cut to enhance work efficiency.
  • It comes with angle flaps which help in wheel positioning.
  • The flap disc cuts the target metal layers without demanding the material underneath.

Cons

  • The flap disc can cause paint clogging when used for paint removal.
  • It requires that you apply more pressure on the grinding surface.

The flap disc can penetrate hard metal, resulting in efficient and sharp lawn mower blades. The pack is made up of 10, type 27 grinding wheels.

How Do You Sharpen a Lawn Mower with a Flap Disc?

To sharpen your mower blades, the first step to take is to wear your safety gear such as work gloves, eye, and ear protection. Here are some tips on how to sharpen your lawn mower blades with a flap disc:

  • Use a vise to clamp the blade. 
  • Align the mower blade cutting edge with the grinder’s blade.
  • Move it slowly against the edge of the blade.
  • Ensure that you do it on the existing edge and make sure that there are no rough spots.
  • After completing one edge, repeat the process by turning it over again.

If you feel that the sharpening process is complete, endeavor to check it by testing it on a blade of grass. It must be able to cut it easily.

Do Wet Grass Dull Mower Blades?

Yes, cutting wet grass can make your mower blades dull. Ensure that you clean the blade thoroughly after mowing wet grass to keep the cut sharp. For optimal cutting performance, sharpen the blades regularly.