Do's and Don'ts of Flap Discs

To prevent a flap disc breakage and personal injury, please review and comply with the following list of Do's and Don’ts.

  • Do store abrasive flap disc at the recommended 40-50% relative humidity and 60-80° F (15 to 29° C).

  • Do rotate stock. Use flap discs on a first in, first out basis.

  • Do store flap discs in their original containers and away from water or other fluids.

  • Do comply with ANSI B7.7, OSHA, and all safety materials provided with the flap discs, machines, and the tools.

  • Do check all flap discs for damage to the flaps and backing plate.

  • Do discard any damaged flap discs.

  • Do select a flap disc suitable for your application.

  • Do disconnect the tool from power supply before changing a flap disc.

  • Do use flap discs that are 4" and larger on guarded angle grinders/sanders.

  • Do match flap disc size with grinder/sander (e.g. 7" flap disc for a 7" grinder/sander).

  • Do check machine speed against established safe operating speed marked on the flap disc. Never exceed the rated speed of a flap disc.

  • Do wear proper personal protection such as ANSI approved impact-resistant eye and face protection, arm guards, apron, gloves, safety shoes, hearing protection, etc. The use of a respirator is required where harmful materials may be produced by the operation, such as wood dust, toxic metal particles, etc.

  • Do test run your flap disc in an enclosed area such as a barrel at operating speed for one full minute before using it.

  • Do use proper mounting equipment supplied by the tool or flap disc manufacturer.

  • Do use side handle when furnished with your angle grinder/sander.

  • Do use work-piece fixture when grinding or sanding small work-pieces that may be thrown during the grinding or sanding operation.

  • Do maintain your tools as if your life depends on it.

  • Do use flap disc at the proper angle. Type 27 flap discs should be used at 0°-15° angle and Type 29 flap discs should be used at 15°-25° angle to the work-piece.

  • Do shield bystanders and any flammable materials from the spark/debris stream (shower).

  • Do review all applicable MSDS (Material Safety Data Sheets) before using this product.

  • Do visit the abrasive manufacturer’s website for additional safety information.

  • Do contact your abrasive manufacturer if you have any safety questions.

  • Don’t use on pistol grip air sanders or any other improper tool.
  • Don’t store abrasive flap discs on concrete floors, near open windows, in direct sunlight, or near heat sources such as radiators or steam pipes.
  • Don’t use flap discs that have been dropped or appear damaged in any way.
  • Don’t remove the side handle furnished with the machine.
  • Don’t wear any loose clothing, jewelry, or any item that may snag onto moving equipment.
  • Don’t exceed the maximum RPM marked on the flap disc.
  • Don’t use a flap disc to cut.
  • Don’t install a flap disc onto a machine NOT in good working condition.
  • Don’t jam the flap disc into a work-piece.
  • Don’t create a hazard. Shield any nearby bystanders and any flammable materials from the spark/ debris stream (shower).
  • Don’t allow the flap disc to “load up” with the material you are abrading.
  • Don’t use a flap disc if you have not reviewed all of the safety materials and have not been properly trained in the use of the tool and flap disc.

Remember, flap disc grinding can be hazardous to operators and bystanders. If a flap disc breaks in operation, there can be serious injury to eyes, face or other parts of the body not protected by adequate equipment. Grinding sparks and dust particles may also cause serious injury by contact or inhalation.

Check out more of our Do's and Don'ts!

Do's and Don'ts of Bench Grinding Wheels

Do's and Don'ts of Chop Saw Wheels

Do's and Don'ts of Portable Cut-Off Wheels

Do's and Don'ts of Type 27 Grinding Wheels


For additional information on this topic or if you need any other abrasive safety information, please review ANSI, OSHA and all literature provided by the coated abrasive and machine manufacturer. You may contact the Saint-Gobain Product Safety Department at (508) 795-2317, Fax (508) 795-5120 or contact your Saint-Gobain Abrasives representative with any safety related questions.