Diamond drills: types and features

Diamond drills are made from high-strength polycrystalline diamonds for drilling holes in concrete, marble, granite, ceramics, and other hard non-metallic materials. Diamond-coated drills are often used to perform particularly difficult jobs when the use of carbide drills is difficult or impossible. They are used in stone processing, in construction and installation works and in everyday life.

Types of diamond drills

Today, diamond drills can have different shapes of working attachments:

• tubular-cylindrical;
• solid-cylindrical (sintered);
• conical;
• spherical.

Each type of drill has its own characteristics during operation, so let's consider what needs to be taken into account when choosing this tool.

Tubular drills with diamond coating

One of the main advantages of a drill with diamond coating is the increased productivity of the process. This happens because when used, it is subjected to a small end pressure, which allows the tool to be used for drilling at high speeds.

Among the main disadvantages of a tubular drill, one can note its insignificant service life. 

Conical diamond drills

In appearance, this tool is practically no different from conventional metal drills, and differs only in the material it is made of. One of the main advantages of this type of tool is its high wear resistance.

The whole point is that the production of cone-type drills uses the technology of applying a diamond coating using the vacuum-diffusion method, which allows creating a coating where the number of diamond grains is increased by 2-2.5 times. When using this method, the gaps between the diamond grains are filled with metal, which ensures the highest durability of the formed coating.

Drills with sintered diamond chips

These drills are distinguished by a long service life and high reliability. If you follow all the technological recommendations for work, then the bar of a hundred drilled holes is easily conquered. Among the disadvantages of these drills is that during operation the tool is subjected to significant end pressure, which does not allow the use of high processing speeds.

Cooling

To increase the service life of the tool, it is advisable to drill with water cooling. If you do not work with a drilling machine with an internal water supply, then, during the drilling process, you must add water to the hole yourself. It is also necessary to periodically lower the drill itself into the water. It is also recommended not to allow the segments to heat up, as an overheated segment begins to melt its own solder, resulting in metal shavings that clog the hole and spoil the drill.

Also, after each drilled hole, it is necessary to remove the piece of stone that remains inside the drill, as a core left in the drill can lead to overheating or curvature of the drill barrel.

It should be remembered that, over time, when working with diamond drills, sharp edges wear out and become dull. Therefore, the working layer should be regularly "opened", that is, dry drilled through the abrasive composition.