The panes usually consist of a synthetic resin mixture reinforced with glass fibres. This makes it resistant to high forces and temperatures. Basically, the grinding and cutting wheels are divided into metal and stone. With a stone wheel you can also process concrete, marble and other special materials of this class. A metal disc can be used to process steel, cast iron and many other metals.
Cutting discs for metal, however, are not very suitable for cutting copper pipes. This creates a lot of burr which narrows the pipe opening. When laying heating pipes, the constriction is usually noticeable in the form of noise or other unpleasant noises.
An angle grinder with quick-clamping system helps you if you change your discs very often.
However, there are not only differences in the materials that can be machined. Different disks are needed for cutting workpieces than for grinding. Discs that are used for grinding have a slightly different composition. In principle, it is possible to carry out grinding work with a cut-off wheel. This, however, results in very heavy wear. The reason for the high wear is that the glass fibre reinforcement on the surface dissolves during grinding.
Then the cut-off wheel loses its hold and wears within a few minutes. Therefore, grinding wheels are much thicker than cutting wheels. They are also colloquially referred to as rough grinding wheels. They are suitable for high material removal. It is therefore easy to remove rust or old layers of paint from the workpieces. Roughing discs are also suitable for removing surface irregularities.
There are also extra thin flex discs. These have a thickness of about one millimeter. Since they only make very narrow cuts, they are highly efficient. Such cut-off wheels are ideally suited for precision cuts. When working with thin cut-off wheels, it is only necessary to ensure that the angle grinder is not held in such a way that the wheel cants. It cannot withstand high bending forces.
When choosing the right disc, however, the diameter also plays an important role. There are basically these four standardized sizes:
- 115 millimetres
- 125 millimeters
- 178 millimeters
- 230 millimeters
Of course, there are also larger cut-off wheels with diameters of up to 400 millimetres. However, these are no longer used with angle grinders, but with special equipment driven by combustion engines.
The different disc sizes are suitable for angle grinders in different performance classes. Smaller angle grinders often referred to as one-hand angle grinders, are equipped with discs with a diameter of 115 or 125 millimetres. These machines have an output of about 600 to 800 watts. A medium-sized Flex works with a disc that has a diameter of 178 millimeters. A cut-off wheel with a diameter of 125 millimeters can also easily be clamped on such a device.
The motor power of these devices is about 1400 to 1800 watts. Angle grinders that are suitable for grinding and cutting wheels with a diameter of up to 230 millimeters achieve an output of more than 2000 watts. It is advantageous to use two angle grinders of different sizes. Since the discs are subject to wear as a result of work, the heavily worn disc can still be used on a smaller flex. In this way, the grinding wheels can be used much better.
The holes for the mounting are identical for all wheel sizes. This makes it easy to change to another machine at any time.
Discs of different sizes are also operated at different speeds. In the smaller models with 115 and 125 millimetre diameters, work is usually carried out at around 10,000 revolutions per minute. If the cutting disc has a diameter of 178 millimeters, it rotates at an average of 8,500 revolutions per minute. In the largest versions with a diameter of 230 millimeters, only about 6,500 revolutions per minute are achieved.
The slightly more expensive diamond discs represent a special form. These are coated with diamond dust and therefore very wear-resistant. They are particularly suitable for cutting different stone materials and especially tiles. You can also cut tiles with a conventional stone disc, but then due to the hard ceramics high wear arises. So if you have to cut a lot of tiles, the purchase of a diamond cutting disc is definitely worthwhile. The additional costs for such a disc are lower than the purchase price.
For angle grinders, wire brush attachments are also available in addition to the cutting, grinding and roughing wheels. These are mounted on the spindle to which the discs are otherwise attached. Wire brush attachments are ideal for derusting or cleaning extremely dirty equipment. The advantage of working with a wire brush attachment is that hardly any material is removed. This is extremely important if a workpiece is to retain its original dimensions in any case.
When working with such an attachment there are usually no sparks flying, but for safety reasons you should never work without safety goggles. Small metal splinters or rust particles fly through the area like small projectiles. If these particles hit the hands or arms, it is a bit unpleasant. In the sensitive eyes, however, they cause serious injuries that lead to impaired vision.
Instead of a wire brush attachment, a serrated washer can also be used. This usually achieves a slightly higher abrasion so that it can also be used to carry out various preliminary work. It is particularly advantageous that the diamond cutting disc, the serrated discs and also the wire brushes are all provided with standardised mounting holes. Therefore, all discs and brushes can be used on all angle grinders. There are no manufacturer-specific standards for these power tools.
Any disc can be used with any flex from any manufacturer.