The different types of Grinding Discs

19 April 2018
When picking a grinding wheel, there are a lot of factors that you need to consider before you make your purchase.

A grinder has the potential to be one of the most hazardous machines in the workshop, mainly because of the wheels that are fitted to it. To ensure that you keep yourself and your workshop safe, you should follow strict guidelines at all times:

Speed Rating: Before purchasing your wheel, you should always check the running speed of the grinder compared to the wheel. As a rule of thumb, the grinders running speed should never be more than the wheel’s maximum speed due to the risk of the wheel breaking or exploding.

Abrasive Wheels Course: In the work environment it is compulsory to have been on an abrasive wheels training course before working on this type of machine. At VJ Technology, we offer a comprehensive on-site training course to help make sure that you are fully prepared to use abrasive wheel equipment.

Wheel Integrity: Every wheel should be checked after unpacking for any signs of damage. If you can identify any damage, the wheel must not be used.

Storage: Wheels should be stored in a dry area where they will not be susceptible to rough treatment or rooms where there are major temperature changes as this can damage the bond in the wheels.

Personal Protective Equipment (PPE): Goggles should always be worn when the machine is in use; a suitable dust mask is also a must if dust extraction isn’t available. Other PPE such as overcoats and ear defenders are not essential but preferable.

Different Abrasive Materials

Aluminium Oxide

White Grinding Wheels: White grinding wheels tend to be very friable as they’re made from pure Aluminium Oxide. The crystals can break down very quickly, as those with dull cutting edges are replaced with sharp cutting edges. Due to their friable nature these wheels can lose their shape very quickly and a dressing stick will have to be used regularly to avoid this.
Suitable Materials: Steel
Uses: 60 and 80g suitable for roughing out tools; 100g for finishing

Pink Grinding Wheels: Also made from Aluminium Oxide, pink wheels have added Chromium Oxide, which makes the grains of the wheel tougher, which allows the wheel to hold its shape for longer. Pink wheels are considered semi-friable, but can become as friable as white wheels when used incorrectly.
Suitable Materials: Steel and some high speed steel
Uses: Grinding the fine edge on hand tools.

Grey Grinding Wheels: Also made from Aluminium Oxide, grey wheels and commonly supplied with the grinder and are very durable.
Suitable Materials: Carbon steel
Uses: General workshop, production and rough grinding

Silicone Carbide

Green Grinding Wheels: ‘Green’ wheels have an extremely sharp grit, are very rigid and hold their shape for a long time.
Suitable Materials: Tungsten carbide, titanium and the hardest steels
Uses: Precision grinding and surface finishing