Basic Safety Rules For The Use Of Grinding Wheels

The recommendations as set out below are only a summary of the most important precautions. All users must strictly comply with the safety instructions existing in the laws, regulations and technical standards of their country.

Rappold - Winterthur strongly recommend to visit the homepage of FEPA, the European Association of Grinding Wheel Manufacturers, who have an excellent summary of most relevant safety regulations.
http://www.fepa-abrasives.org

Download: Summary FEPA Safety Recommandations

Download: Checklist Safety

 

Recommandation by Winterthur Technology Group

  • Read the safety rules pertaining to your country. Consult the Rappold - Winterthur main catalogue’s safety section.
  • Inspect products for defects when receiving and, again, prior to mounting.
  • Store grinding wheels in suitable rooms fitted with appropriate racks.
  • Ensure that permissible RPM and/or surface speed in m/s or sfpm correspond to grinding wheel and machine intended for use.
  • Use paper or plastic blotters between wheel and machine intended for use.
  • Use torque wrench when tightening flange nuts.
  • Inspect all guards and other safety features for proper functioning.
  • Wear safety glasses.
  • Start machine, step out of the way, and run machine at idle speed for 1 minute prior to cutting metal.
  • Operate machine according to machine and wheel instructions.



 

Please avoid under every circumstances

  • NEVER, EVER run a grinding wheel at higher surface speed (m/s or sfpm) than marked on the wheel.
  • Never mount a vitrified grinding wheel without prior ring test. If dull sounds occurs, do not use wheel.
  • Do not force a grinding wheel on flange, shaft or arbour.
  • Do not operate a grinding machine with safety devices removed.
  • Do not use a grinding wheel without wearing safety glasses.
  • Do not side-grind with a wheel not intended for this purpose

 IF IN DOUBT, ASK YOUR WHEEL SUPPLIER - WINTERTHUR

 

Further Technical Leads

Ring Test of Vitrified Grinding Wheels

The wheel should be lightly tapped with a non-metallic hammer to the right and the left of the vertical centreline.

  • Light wheels should be held on a finger or on a mandrel
  • Heavier wheels should be placed on the floor, standing upright on their peripheral face. In the case of hard floor surfaces, place a wooden board between the floor and the wheel.

A crack-free vitrified wheel will emit a clear, bell-like ringing sound; a damaged wheel will sound dull. (Resin bonded wheels do not emit the same metallic ring as vitrified wheels).

Note: cracks are often invisible to the eye!

 

 

Mounting of Grinding Wheels

Prior to mounting, ring wheel to ensure that it is sound. Always use blotters between wheel and steel flange. For surface speeds of 50 m/s (10,000 sfpm) or higher, plastic blotters (polypropylene 0.5 mm thick) should be used. If paper blotters are used, moisten them with coolant prior to flange asembly. Paper blotters may require retightening after one day. Always use torque wrench for tightening flange screws.

As per ANSI B7.1-1988, Chapter 6.10.2, apllied torque should not exceed 20 foot pound (27 Newton metres/NM) unless specifically recommended by wheel manufacurer.

Use tightening sequence as illustrated below:

 

Applied torque
specifically for and restricted to Winterthur standard specifications can be taken from the table below. These torque forces aplly only to OD grinding wheel, diamter 400 (16 inch) and lager, wheel width 25 mm (1 inch) and wider. The same spec in finer grit size or harder structure can, of course, be tightened with at least the same torque force.