a straight grinder with a flap wheel
a drawing of someone grinding with a straight grinder and a flap wheel
a flap wheel of maximum 250 millimeters diameter

Terminology: Flap wheels may be used at speeds up to 63m/s. Straight grinders must be fitted with a guard for products 55mm diameter and above.


Flap wheels improperly used can be dangerous: wheels can run at speeds up to 63 m/s on straight grinders and can eject parts at a speed of up to 227 km/h (140 mph) in case of breakage. FEPA has designed this page to provide the essential safety recommendations for use of flap wheels on straight grinders with maximum diameter of 250mm.


Abrasive Products

These recommendations focus on flap wheels for grinding with straight grinders. They can be either coated abrasive or a combination of coated and non-woven abrasives.


Safety recommendations for the use of flap wheels for grinding with straight grinders

80% of the accidents are due to a misuse of the abrasives products. Theis website has been realised by the FEPA experts to spare the end-users to get hurt while using this kind of products.

FEPA general safety principles

Dos & Don’ts for these products

Soon available

What is a safe product? What should I look for?

 FEPA recommends that only products conforming to EN 13743 and marked as such should be used.

Flap wheels not bearing EN 13743 may not conform the highest safety standards.

 All wheels should be examined carefully for damage or defects before fitting on the machine.

How shoud I handle and store de wheels ?12A

 All abrasives wheels are fragile. They should be handled with care.

 Wheel should be stored on a flat, rigid surface, avoiding damp or wide variations in temperature.


How should I fit the wheel on the machine?12C

 Follow carefully the instructions given in the machine handbook.

 Never fit a wheel which is loose or too tight on the flange.

 Tighten only with the tool supplied with the machine.

 Ensure the wheel is properly gripped to prevent slippage, but do not tighten with excessive force. Never use a hammer.

 Keep flanges and screw threads clean and free of burrs and rust.

 Replace distorted or damaged flanges before fitting the wheel.

 Refer to the FEPA recommended mounting check list.


How should I protect myself?

 FEPA recommends the use of following personal protective equipment (often written PPE) : 

  • Eye protection
  • Ear protection (ear sets)
  • Hand protection (gloves)
  • Lung protection (dust mask, also called respirator)

 Never remove the protective machine guard where fitted and make sure it is properly adjusted to deflect debris away from you.

 Ensure that no other person is at risk, especially near the machine while working.

How should I handle the wheel after use?12E

 Before storing the machine or transporting it to another location, always remove the wheel and store it as recommended.

 Always carefully examine the wheel for damage or defects, and destroy and discard if damaged.

 Do not fit worn out wheels on a smaller machine. Destroy them.

 When disposing of worn out or defective wheels, it is recommended to damage them to prevent someone from removing them from waste and re-using them.


How can I get proper training?

 It is a legal requirement for all employees involved in the use of abrasives wheels to be properly trained and also re-trained on a regular basis. They should consult their employer if they have not received this training.

 The wheel manufacturer or supplier can advise you on suitable accredited training providers. 

 As a private consumer, you should read carefully the safety information found in:

  • The grinding machine handbook
  • The FEPA general safety principles leaflet (see above)
  • The FEPA safety leaflet for this specific application (soon available)  



This website is intended to give information on safe use of abrasives in compliance with European standards, and not to give advice on product selection. You should read the information given on the product or its packaging to determine suitability. For any specific question, contact the retailor who supplied you the product.