Choosing the right diamond blade for an angle grinder, circular saw or wall chaser is not so easy these days - especially if you are dealing with it all for the first time. The incredible number of different blades dazzles your eyes, and in order to decide what you need, you need to know exactly what material you plan to cut and under what conditions the work will take place. Understanding these two factors will not only allow you to achieve the desired quality of cut and maximum saw performance, but will also save you time and sometimes even save your health. That is why, when choosing a disc for cutting or grinding, you should abandon obsolete abrasive blades and pay attention, first of all, to diamond discs.
Characteristics and scope
In order for the work to proceed without problems, the cutting wheel must be replaced in a timely manner. That is why this is the most consumable part when operating an angle grinder. In general, there are simple and diamond discs, but we will consider the second type, because it is the most popular and is primarily valued for its durability. However, cutting wheels can also vary depending on the surface they are intended for.
Types
According to the type of design and manufacturing technology, there are circles:
- Segmented - the body is divided by slots that divide the surface into several sections. Thanks to this device, the wheel is more resistant to mechanical loads and temperature changes, has greater productivity, but the cut after it will not be of the highest quality. Well suited for rough structures.
- Solid - have a cutting tape interspersed with artificial diamonds, running along the edge of the circle. The main purpose is cutting ceramic products and other types of materials that require precision when working with them.
- Turbo discs - have an oblique notch along the edge of the circle, which makes cutting more accurate than segmented discs. Due to its design features, it can withstand high temperature loads, and therefore has an increased cutting speed. Works with a variety of mineral materials, ranging from sandstone to granite.
- Turbo segmented - a hybrid of the first and third types, taking all the best from them, is universal in use and has high performance.
Working principle of diamond cutting disc
Most diamond blades are used on angle grinders with speeds up to 12,000 rpm. The maximum number of revolutions that the best wheels can withstand is 13900 rpm, but there are not too many tools capable of developing them when cutting.
Only the diamond itself comes into contact with the surface being treated - it protrudes above the surface of the rim and, when rotated, abrades the material into fine dust. The multi-layer structure of the cutting edge ensures that the disc is always ready for work - diamonds that have worn out or flown out of the socket are replaced by others that are located in a lower layer of the rim.
Excess heat is dissipated through the disk body, but, nevertheless, it heats up to fairly high temperatures, which requires compliance with certain safety rules when dry cutting.
The durability of the wheel and the effectiveness of its use depend on the size of the diamonds. Large ones provide efficient operation, but wear out quickly, small ones cut very accurately, but more slowly, their service life is 25 - 30% longer than that of tools with large crystal fractions.
How to choose the right one for an angle grinder?
First of all, you need to decide what type of material you will have to work with and what size the surface to be processed will be. This affects what kind of circle design is needed. Most cutting wheels are designed for cutting non-metallic materials, such as glass, concrete or brick, but there are also those that are made specifically for metal work. Therefore, you need to take into account that for each type of working surface there is its own type of cutting wheel.
One of the basic rules for choosing discs is that for “soft” materials, purchase wheels that have a cutting surface with a hard diamond surround; for “hard” materials, on the contrary, with a “soft” one. The reason is that when cutting hard materials, diamonds wear out very quickly, and new ones must appear to replace them as quickly as possible. On the contrary, in a hard cutting strip, diamond inclusions will last much longer.
Design of diamond cutting discs
Structurally, a diamond disk is a steel circle with a cutting part and slots over the entire area, which facilitate heat removal and reduce deformation stress. Diamonds are interspersed throughout the rim of the disc. They are inserted into a rim made of nickel, zinc, cobalt and tin alloys. With a linear speed of up to 80 m/s and enormous frictional forces, the fastening must be extremely strong, which is achieved using special technologies.
To ensure that the cutting part is held under heavy loads, they can be secured by laser welding, sintering, electroplating or soldering. Soldering is only used on cutting discs using water-cooled machines.
Depending on the method of securing the diamond, the purpose of the disc is determined. Galvanically fixed diamonds are designed to work with soft types of natural stone, processed by laser welding and sintering, especially segmented ones - for all types of hard materials in a dry and “wet” method.
The holes and slots are located strictly symmetrically, and the mass of diamonds is also balanced in diametrically opposite directions. This eliminates vibration and “beating” of the disk and ensures uniform cutting. But you can use dry cutting wheels only to make a straight cut - with a curved trajectory, the disc can not only lose diamonds, but also be destroyed. This type of instrument is very sensitive to lateral loads.
1. Damping slots. 2. Cutting layer. 3. Mounting hole. 4. Steel disk.
Size
The diameter of the disc affects such important parameters as cutting depth and working speed. On average, the sizes of cutting wheels range from 115 mm to 230 mm, sometimes reaching more than 300 mm. The latter are intended mainly for powerful mechanisms - such as stationary cutting machines or gas cutters.
Expert opinion
Levin Dmitry Konstantinovich
Under no circumstances try to put a larger disc than necessary on an angle grinder. In this case, you will have to remove the protective casing, and this can lead to serious work-related injuries, since if the circle breaks naturally, the debris can seriously injure you. You can work ONLY with a casing and full protection.
Cutting edge type
Segmental
Designed for quick dry cutting of asphalt, wet concrete, ceramics, reinforced concrete, granite, natural stone, brick. The cutting edge of such products is divided into separate segments, between which there are grooves that remove heat. The shape of the grooves depends on the material the blade is intended to cut. So, to work with asphalt, a wide gap is required. Smaller segments reduce vibration and promote better cooling.
The diamond segments on the discs are secured by laser welding. Used for work requiring greater speed and productivity, but with low requirements for cutting accuracy
With continuous edge
They do not have cutouts on the body and are intended for work that requires the most precise cutting. The speed of work on disks with a solid edge is lower than that of segmented ones, but the resulting cuts are very smooth, and the edge has no defects or chips.
Used on stationary and mobile machines. Divided into two subspecies:
- for wet cutting – used only in stationary tools;
- for dry cutting - in hand-held and stationary tools (grinders, etc.).
Used for cutting ceramic tiles, glass, marble, tiles, artificial and natural stone, and other fragile materials.
Turbo
Used for wet and dry cutting. They have a wavy cutting edge and holes that provide additional heat dissipation. Used for processing concrete, granite, paving slabs, brick, building stone. They provide a clean edge; when cutting reinforced concrete, they react differently to pieces of reinforcement than other types of discs, so it is best to use these discs for cutting such material. Soft cutting allows you to get edges without chipping, so processing porcelain stoneware, stone slabs and ceramic tiles is allowed.
Improved versions of Turbo discs: Wave, Super-Turbo, Turbo+ - their wave-shaped, rather than flat, shape improves cooling and emission of dust and other cutting products.
Turbo segment
Turbo segment discs have a wavy edge and special ventilation holes in the body. Combines the advantages of segment and turbo cutting-off diamond wheels. Provides fast cutting with a clean edge.
The distribution of diamonds in the cutting edge also affects the scope of application of the discs. Diamonds can be distributed in a conventional or sandwich manner. With conventional distribution, the diamond component is applied evenly, with sandwich distribution it is calculated. In addition, fine-grained diamonds are used for processing hard materials, and coarse-grained diamonds for soft ones.
Tips on how to extend service life
What type of diamond blades do you work with most often?
SolidSegmented
There are a few simple tips to ensure that a newly purchased cutting wheel lasts as long as possible and works out the entire amount spent on it:
- Discs with a larger wheel diameter will work longer because they have a low load on the cutting crystals (but remember that the size of the wheel must be selected according to the type of mechanism!).
- The more powerful the tool, the more stable its speed, thus the disc wears out less.
- Choosing the right disc type for the material.
- Never exceed the permissible speed.
Advantages and disadvantages
The devices under consideration have a lot of positive properties, which makes them universal. An angle grinder with a diamond blade is capable of performing any task of cutting and grinding various types of materials. The advantages of diamond blades are due to the following properties:
- Versatility. Using one wheel you can cut various materials
- Work safety. It is very important to note that the products in question are not capable of scattering during operation, as is typical for low-quality abrasive wheels
- High speed of work. The use of a diamond disc allows you to carry out work much faster compared to abrasive wheels
- Low noise level. When processing various materials, diamond products have a low noise level, unlike abrasive ones.
- High accuracy. During the cutting process with a diamond wheel, the master sees the cut line, allowing him to obtain the most accurate results.
- Long service life. Even with daily use of the product, its service life remains quite long, while abrasive materials are erased with almost one use
Advantages and disadvantages of diamond wheels
A significant disadvantage of the products under consideration is their high cost. This cost is due to the following factors, such as the use of expensive diamond chips, as well as a long service life. The disadvantages also include the undesirable use of a device for sawing metal, as this leads to accelerated wear of the teeth. The process of sawing concrete generates a lot of dust, so it is recommended to carry out the work using a respirator or mask and goggles.
It is important to pay attention! If the disc is intended for wet cutting, then it cannot be used on equipment where this condition is not met. Wet cutting is indicated by a drop on the circle marking.
Cutting Features
Before you start cutting concrete, you need to determine its type and structure. The following rules apply:
- For cutting depths of more than 10 cm, special discs are used that are capable of sawing reinforcement. It should be taken into account that reinforcement schemes can be very different.
- Fresh and old material have different properties, and therefore different wheels need to be selected for them.
- To cut basalt and quartz, you need to use discs with a soft binder so that the diamond substance is renewed faster.
- The larger the filler, the slower the sawing occurs.
In order to cut a concrete slab, block or other structure, 2 main technologies are used:
- Wet. It is carried out with the addition of water continuously, quickly and without the formation of dust.
- Dry. It is carried out in several stages to clean the material and equipment from dust, and also to give the cutting tool time to cool.
Important! Before starting work, you need to draw a cutting line in a straight line with chalk. Next, to make the cut as smooth as possible, it is necessary to secure the bars along the edges and make a shallow starting cut - 5-10 mm. Then perform the main cutting on it.
Video example of cutting a floor slab with a grinder:
Diamond application
The cutting function is performed by a diamond-coated disk. Diamonds are applied to certain areas, and therefore there are two types of products:
- discs with diamond coating over the entire surface;
- circles with spraying on the surface of the teeth.
Abrasive spraying is applied from the end or peripheral surface (ring-shaped or over the entire surface). The volume of the composite containing diamond depends on the geometric dimensions of the working surface, which directly affects the price of the product.
Diamond blade
When choosing, you should consider the width, since thickness only affects durability. The width determines the area of impact on the surface being treated, which determines the performance and operating temperature range.
Discs with a smaller width allow for increased rotation speed and depth of impact. Wide models provide higher precision and cleanliness.
The surface to be treated must be wider than the working layer - this is necessary for its uniform development and self-sharpening.
Safety precautions
The grinder is one of the most traumatic tools that can cause severe injuries to the master.
Safety rules that must be followed:
- All work is performed in special clothing - a protective suit, gloves, construction glasses and a respirator.
- It is forbidden to cut with a grinder without a protective casing and to process workpieces placed in water.
- The cut is performed away from you in order to control the geometry of the cut, holding the tool with both hands.
- Do not put too much pressure on the disc - this can lead to damage and rupture.
- The cable length must be sufficient for free manipulation of the unit. At the same time, you need to place the wire so that it does not get under the disk and under the master’s feet.
- The workpiece should be securely fixed on a workbench or other plane, preferably wooden.
- It is forbidden to hold the grinder vertically and put it aside with the rotating disk.
- All work must be carried out in a well-ventilated area.
When choosing a disk for cutting tiles, you must read the markings indicated on the product. The circle must correspond to the type of material that is planned to be processed, and the diameter must correspond to the model of the grinder.
In addition, you need to follow the recommended speed and select the optimal thickness of the nozzle. Ignoring these principles will not only reduce the quality of work, but may also pose a threat to the health of the master.
Scope of application
Diamond blades are widely used to perform cutting, sharpening or grinding operations on hard non-metallic and metal surfaces. They are used as accessories for:
- tile cutters;
- angle grinders;
- petrol cutters;
- wall chasers;
- stone cutting machines;
- cutting machines and other equipment.
Diamond blades are available for dry and wet cutting. A tool designed for dry cutting is more convenient to use, but requires dust removal and respiratory protection measures during operation. It can be used for both dry and wet cutting. The opposite option (discs with a wet cut for a dry cut) is unacceptable and leads to rapid failure of the tool. The tool is produced with recommendations for use for a specific type of material; there are highly specialized and more universal ones. Manufacturers offer discs designed to work with concrete, asphalt, ceramic tiles, metal and other materials.
The specialization of the disc is influenced by the type of binder and the shape of the working surface - solid, turbo or segmented. The choice of binder determines the heat removal and renewal of the cutting edge. To work with dense, hard materials, a softer binder is selected, which allows the release of a new layer of diamond chips when the previous one is abraded.
Features of selection and operation
When choosing a tool, it is necessary to take into account its outer and mounting diameters, the configuration of the cutting part and the manufacturer’s recommendations. The maximum possible cutting depth depends on the outer diameter; the most common diameters are 115, 125, 180 and 230 mm, the maximum size for hand tools reaches 320 mm, for machine tools – 600 mm. Standard mounting diameters are 22.23 mm for disks up to 230 mm in size and 25.4 mm for disks 300 mm and larger.
When choosing, pay attention to the product labeling. The speed of the tool should not exceed the permissible revolutions per minute indicated on the disc marking. The recommended cutting material and direction of rotation are also indicated.
The main factors that increase the service life of diamond wheels:
- Cutting with a larger diameter reduces the load on the work surface.
- The high power of the tool eliminates the drop in speed.
- Optimal choice and strict adherence to the rules of disk operation.
- Strict adherence to a straight cutting path.
- Elimination of overheating during operation.
- Metered supply of tools. It is advisable to perform deep cuts in several passes; the optimal depth of the pass is equal to the height of the cutting part of the disk.
