A grinder is a very versatile and useful device; however, can be dangerous too, thanks to the discs that are used along with it. There are many different types of grinding discs suitable for different applications and you must also consider a few factors before buying a grinding wheel.
Types of Abrasive Wheels
White Grinding Discs
These are usually very friable since they are made of pure aluminium oxide. The crystals of the disc break down very easily and the dull edges are replaced by very sharp ones. However, since the discs are extremely brittle, they lose their shape very easily and by using a dressing stick, you can prevent this from occurring. White grinding discs are ideal for steel and typically 60g and 80g discs are ideal for roughing out tools, while 100g is suitable for finishing.
Pink Grinding Discs
These are also made from aluminium oxide; however, there is chromium oxide also added that helps to make the grains of the disc tougher. This allows the disc to retain its shape for a longer time. Pink wheels are generally considered as semi-friable, but if used incorrectly, they can become friable like white discs. Pink grinding discs are suitable for steel and some kinds of high-speed steel. These discs are suitable for grinding fine edges on various hand tools.
Grey Grinding Discs
These discs are also made from aluminium oxide and are usually supplied along with the grinding machine. Grey discs are very durable and are ideal to grind carbon steel. Grey grinding discs are usually used for rough grinding, general production and fabrication jobs.
Green Grinding Discs
These discs are quite rigid and contain very sharp grit and can retain their shape for very long. They are suitable for materials like titanium, tungsten carbide and the hardest variety of steels. Green discs are ideal for surface finishing and precision grinding.
Always check the running speed of your grinder in comparison to the grinding disc before buying one. Generally, the running speed of the grinder must not be greater than the maximum speed of the grinding disc because the disc can cause the disc to break or explode.
When you unpack the equipment, check every disc carefully for any damage. If any disc is damaged, then you must not use it.
The grinding discs must be stored in a clean and dry area and should not be handled roughly. The rooms where the discs are stored must not have any major temperature changes as this will damage the bonds of the disc.
While using a grinder with grinding discs, it is a good idea to wear goggles when the machine is in operation. If there is no dust extraction, then it is recommended that you use a dust mask also. Other protective equipment such as ear plugs and overcoats are preferable, but not compulsory.
Course on Abrasive Discs
When you work on a grinder that uses abrasive discs, it is mandatory that you undergo a training course on working on a grinding machine and are well versed in the use of abrasive disc equipment.
Now that you are aware of the various types of grinding discs and the factors that you should consider before buying a grinding disc, you can select the ones that you will use depending on the jobs that you do most of the time. ESCCO provide a range of grinding discs which can be found here