Diamond blade for concrete: cutting and grinding

For cutting porous, cellular and heavy concrete, stone and brick, diamond cutting is currently used, for which discs, ropes, crowns (cutters) and chains are used - all this tool has a diamond coating. Such cutting is widely used for the manufacture of all sorts of holes in the installation of communications, for arranging doorways and window openings, niches, for partial or complete dismantling of buildings and structures. In more detail about this tool will be discussed below, as well as you can watch the thematic video in this article, as an addition to the material.

Diamond cutting nuances

Note. There is a dangerous misconception that a diamond disc over reinforced concrete is able to cut not only the concrete itself, but also the reinforcement that is inside it. This is absolutely not the case - if a disk rotating at high speed with metal is in contact, the diamond coating will instantly melt. Who used such circles, could notice that the deposition is applied from the side, but erased from the end, that is, when friction decreases not the thickness, but the diameter. So, if you want to cut the reinforcement, the direct contact of the two metals will occur, which will lead to the melting of the disc, as a thinner material. Such a process is not feasible under the laws of physics!

Cutting technology

• For the first time such equipment appeared in the 60s of the last century in Western Europe, but reinforced concrete structures were also distributed throughout the world, bringing with them the methods of their most productive processing. In general, diamond cutting is a fairly safe technology, but the concrete dust that always accompanies such processes is extremely dangerous to health - it can cause skin irritation, allergies and even silicosis (with prolonged inhalation).
• In this regard, various safety measures have been developed - dust extraction devices, water supply hoses, and in extreme cases - an ordinary respirator with protective glasses. There are a lot of equipment that is designed with ready-made protective equipment, among them German STIHL and EIBENSTOCK, American ISC BLOUNT INO, Swedish HUSQVARNA, Austrian TYROLIT HYDROSTRESS and so on.
• Such equipment is represented by disc and chain cutters, wall saws, where the disc can reach up to 16,000 mm in diameter with an immersion depth of up to 730 mm (their price is quite high) and, finally. Angle grinders (grinders), where the largest disc is 400 mm in diameter and with a cutting depth of 170 mm.

Types of diamond discs

Note. Depending on what you are going to do with a diamond disc - cut or grind - you can choose the appropriate configuration of the segments, or even do without them. Although you can cut almost any mineral from any of them, the speed and quality of work will depend on it.

• This type of disc as in the top photo is perfect for cutting mineral materials such as brick, stone, concrete, granite and ceramics.. The design of the circle itself is such that, due to the segments, the friction is not constant and its heating is not so intense, therefore, it increases its operational life. However, the process of continuous cutting can take no more than 1-1.5 minutes, after which cooling should follow for at least 20-30 seconds - such instructions are provided by the manufacturer.

• If the diamond coating on the wheel is applied in a continuous strip, without cuts, that is, segments, this suggests that the cut will be clearer and more even than after the segment destruction. This indicates that such a design is more suitable for processing ceramic tiles, marble and even glass, moreover, such a circle can be used for grinding the torn edges of various mineral formations. Considering the moment that in the course of work the friction occurs continuously, then the metal will heat up more strongly, which in turn will cause the deposition to melt, therefore in such situations it is reasonable to use water flow cooling.

• Now look at the top photo, which shows a combined circle, that is, there are no segment grooves, but there is also no solid diamond spraying track - it turns out that this track is divided into segments. This design allows you to use tools for both wet and dry cutting, that is, you can process brick, concrete, ceramics and marble and in any case there will be a good result. Nevertheless, it is still better to use (especially for accurate cutting) exactly the disk that is intended for this - the quality of work from this increases.

• Such flexible turtle disks are designed for polishing concrete, marble or granite without the use of water cooling.. The diamond grain here has a honeycomb structure, which is mounted on a ceramic grid, which allows you to throw the sludge to the side and at the same time cool the surface of the circle. Such circles for polishing can have both the shape of a disk and the shape of a bowl.

• And now we come to what many people say, but poorly represent - it is the simultaneous cutting or polishing of concrete with metal, that is, with such circles, which are usually called turtles, you can saw through reinforced concrete pillar. But here the design is significantly different from the usual diamond disc - here the features of the grinding diamond cup with an elastic wheel are combined. In appearance, it is very similar to the usual abrasive, only thicker, but in the composition contains polymers with copper powder, which significantly increases its wear resistance and efficiency.
• Of course, cutting of reinforced concrete with diamond circles of this type is not provided for directly - the main focus is on grinding concrete, but, nevertheless, it is quite possible that they are successfully used in practice by master finishers and builders. У таких черепашек есть одна особенность, это тип «Металл», который как раз и указывает на то, что ним можно обрабатывать не только минеральные, но и металлические конструкции. Конечно, процесс резки здесь значительно медленнее, чем у любого другого диска с узкой специализированной направленностью, зато возможны вот такие комбинации.

Note. The choice of disc diameter mainly depends on the parameters of the instrument, that is, the capabilities of the seat where this disc is inserted.

Knowledge that is required for the average consumer

Spraying is made of artificial stone, and these pieces are pressed into a metal binder, while the diamonds can be of different sizes and different quality (which, in fact, depends on the cost of a circle), and also binders can be different.

From the change in the quality of spraying, that is, the quality of the stone itself, its concentration in a certain area and the composition of the binder component, the necessary segments are obtained for which the production orientation is already determined (dry, wet or universal cutting).

It is noteworthy that for dry cutting on a steel base the segments are attached using laser welding, while for wet cutting they are fixed by silver soldering.

At the moment, a new technology HDS (HIGH DENSITY SINTRED) has been developed - this is a high-precision powder soldering, with which the deposition is carried out at the highest quality, using the highest quality artificial diamond segments. It is noteworthy that this technology allows the use of circles with different segments not only for wet, but also for dry processing.

This method of soldering does not leave a neutral zone between the main part of the disk and the segments, therefore, here the cutting part can be used at 100%.

Совет. Для того чтобы удостовериться, что вы берёте товар именно такого качества, обратите внимание на его этикетку, там должна быть надпись на английском языке «With HDS technology» (с помощью технологии HDS).

To achieve the cutting effect, with the help of ceramic sharpening, the segments are opened (ground) to a depth sufficient to expose the first pieces of diamond grains. After that, the circle is ready for operation, but it has a cutting direction, so manufacturers usually indicate it with arrows on the label. If they do not, then the direction must be determined empirically.

To make the most optimal choice, you need to clearly understand what diameter and shape of the teeth are suitable for the machine that you will use, as well as the properties of the material being processed. Of course, it is undesirable to use a circle with a larger diameter than is assumed by the carrier; therefore, if necessary, it is better to take another unit.

For example, you cannot drive 70 mm or 80 mm with a 125 mm disk, here you will need a circle with a diameter of 230 mm, therefore, you need to purchase a large-sized angle grinder (Bulgarian) rather than removing the casing with a small one to install a large cutting element - it is dangerous.

In addition, the internal diameter can also be different, therefore, it is chosen accordingly with the shaft of the grinding and cutting machine, but if the shaft is still smaller, then there are various nozzles for this. In no case can you clamp the circle when its inner hole is larger than the diameter of the shaft - this will in any case lead to decentralization and, as a result, to a disk breakdown, and in the worst case, even to trauma.

The following ratios of inner and outer diameter are most common:

• For discs from 155 mm to 230 mm per angle grinder, the hole has 22.2 mm (dry cut segments);
• Outer diameter from 150 mm to 350 mm for machine cutting, the hole is either 25.4 mm or 30.0 mm (wet cutting);
• The outer diameter from 300 mm to 400 mm for asphalt and manual cutters have an opening of 25.4 mm (dry and wet cutting).

If you are going to do any repairs yourself, then you probably already know the material you are working with, so choose the appropriate segmentation - dry or wet cutting. In the event that inconsistency is foreseen, then, of course, you can whiten a universal circle, but if you have to cut a lot, then it is better for each of the materials to choose a suitable cut.

Do not forget that different countries and manufacturers can use a different distinctive marking, so if you do not understand the inscription - pay attention to the teeth or their absence and the principle of segmentation - we told about it above.

При определении типа обрабатываемого материала следует в первую очередь обращать внимание не на его твёрдость или мягкость, а на абразивность - этот фактор более всего «садит» диск. К мягким неабразивным материалам можно отнести мрамор, а к твёрдым - все остекленевшие типа клинкера. А вот гранит или тяжёлый бетон из твёрдых материалов и силикат, шамот или асфальт из мягких можно отнести к абразивной группе.

Conclusion

In conclusion, it can be said that for abrasive materials it is better to choose professional discs, with better coating. The same can be said about diamond drilling of holes in concrete - the higher the quality of spraying - the faster the process and the longer the service life of the tool.