Safety Guide for using Grinding, Cutting and Flap Disk Wheels

Abrasive wheels have a selection of safety warnings, recommendations and usage restrictions marked directly on the product. It is not always possible to include all safety information on the wheel itself. Therefore, the operator must read and follow all instructions supplied in or on the product container, as well as those marked on the product itself.

The most common causes of wheel breakage are due to improper mounting of a wheel, improper speeds, abusive operation and/or careless handling of the wheel and/or power tool. It is the user’s responsibility to regularly inspect wheels and power tools. Inspect regularly to ensure that the mounting flanges are in good condition, of the proper size and shape, and the speed governing device is functioning properly. Always comply with ANSI Safety Code B7.1 and B175.4, OSHA, and CSA Safety Regulations.

Always wear safety equipment appropriate for the job. This includes protective eye wear, hearing protection, respiratory protection, body protection and gloves. Tie back long hair and do not wear loose clothing, ties or jewellery.

Major Causes of Abrasive Wheel Breakages:

  • Using a wheel damaged during transportation, storage or a result of careless handling
  • Machine speed higher than the grinding wheel speed
  • Improper mounting of the grinding wheel
  • Jamming the grinding wheel into the work piece
  • Using excess force, so the tool’s motor slows noticeably or the work piece gets hot
  • Grinding using the wrong surface of the grinding wheel


  • Always store and handle wheels carefully – they are easily damaged
  • Always check all wheels for cracks or other damage before mounting
  • Always store wheels in dry, frost-free conditions, avoiding wide variations in temperature and moisture
  • Always check machine speed against the established maximum safe operating speed marked on the wheel
  • Always use mounting blotters when supplied with the wheel
  • Always make sure wheel hole, threaded or unthreaded, fits machine arbor properly and that the flanges are clean, flat and of the proper type for the wheel you are mounting
  • Always use a safety guard that covers at least ½ of the abrasive wheel
  • Always run a newly mounted wheel in a protected area with guard in place for at least 1 minute before grinding
  • Always follow the warnings and instructions for your machine
  • Always wear protective safety glasses (certified ANSI Z87.1) and additional eye, face, hearing, and respiratory protection
  • Always wear protective clothing, making sure no part of your body is exposed
    • This may include heavy-duty work gloves, apron, long sleeves and pants and a full face shield
  • Always use dust controls and/or protective measures appropriate to the material being ground
  • Always firmly secure and support the work piece
  • Always disconnect the tool from the power source when changing blades


  • Never use wheels that have been dropped or otherwise damaged
  • Never use a wheel that is not designed for the specific application you are using it for
  • Never grind or cut material for which the wheel has not been specifically designed
  • Never use a product if it cannot be properly identified
  • Never use a cut-off wheel using a die grinder (if using a small cut-off wheel requiring a grinder tool, only use a cut-off grinder)
  • Never use, or continue to use, a wheel which is not functioning properly (ie., out-of-balance, etc.)
  • Never use a wheel that has a speed rated less than the speed of the grinder
  • Never force a wheel onto a machine or alter the size of the mounting hole
  • Never use excessive pressure when mounting the wheel between flanges. Tighten nut only enough to hold wheel firmly in place
  • Never use mounting flanges that are not clean, flat and free of burrs or other surface imperfections
  • Never use excessive force or shock when cutting or grinding
  • Never twist, apply side pressure or grind using Type 1 wheel
  • Never apply heavy grinding pressure when using a thin Type 27 depressed center grinding wheel (applies to wheel thickness <1/4”)
  • Never take a cold wheel and introduce it into a hot operation, as thermal shock can break the wheel
  • Never handle a machine carelessly. Stop wheel on work and use racks or hooks to support machine when not in use.
  • Never use relieved or recessed flanges with threaded hole cup wheels cones or plugs
  • Never mount more than one wheel on a single arbor
  • Never start the machine with the wheel already in contact with the work piece
  • Never position your body in line with the wheel
  • Never use wheels near flammable materials and gasses

Exposure to dust generated from work piece and/or abrasive materials can result in lung damage and/or other physical injury. Work outside, use dust capture or local exhaust as stated in the MSDS. Wear government-approved respiratory protection and eye, face, hearing and skin protection. Failure to follow this warning can result in serious lung damage and/or physical injury.

Read the Material Safety Data Sheet (MSDS) before using any materials.

Contact the suppliers of the work piece materials and abrasive materials for copies of the MSDS if one is not readily available.

Label Icons Explained

MIBRO abrasive wheels include various icons that help to explain the following:

  • What material to use the wheel on
  • What power tool to use the wheel with
  • How the wheel should be used

There are also icons showing important safety requirements for wearing protective eyewear, hearing protection, respiratory protection, body protection and gloves.


Always wear protective safety glasses (certified ANSI Z87.1) and additional eye, face, hearing and respiratory protection
Always wear protective gloves


3-inch Cut-off Tool
Angle Grinder
Portable Saw
Hi-Speed Portable Saw
Stationary Chop Saw


Use for 90° Cutting Only
Do Not Use for Cutting
Grinding – Use at 15° – 30° Angle
Do Not Use for Grinding


Masonry and Concrete