Hardened Steel Hole Drilling
It is impossible to provide all the holes and niches in the walls during the construction of the premises. Therefore, after the construction of the monolith, it is necessary to drill it.
The most common structural material is concrete. The technique for making holes in this material is different from the processing of wood, brick and metal.
Concrete Drilling. Pitfalls
- Concrete forms a lot of dust during processing. It is harmful to the respiratory system., In addition, abrasive particles clog into the air vents of the instrument. Cooling is difficult, and the dust that gets inside. Contributes to accelerated wear. Suspension traps must be used. There are special nozzles for a vacuum cleaner, sometimes just enough to substitute the container.
- The structure of the concrete does not form chips, so the removal of material from a deep hole is difficult. In order not to overload the drill, it is necessary to periodically (every 3-5 cm of passage) clean the pit with a vacuum cleaner. When working in a hole clogged with sludge, you can break the drill.
- Abrasive components of concrete contribute to strong heat from friction. The metal of the drill is “released”, loses its hardness and quickly grinds. Therefore, it is desirable to provide fluid cooling, or at least take breaks during continuous drilling.
- The power tool for drilling concrete (drills, perforators) has considerable weight. It is difficult to control the horizontal level. Therefore, during such work it is recommended to equip the tool body with a small bubble level.
- Concrete is a heterogeneous material. In the thickness of the wall come across solid stones, steel reinforcement. When hit by such an obstacle, the drill tends to leave the trajectory. If you come across an armature. You should choose a different location for the hole or go through the site using a metal drill. Then continue to work again with the previous nozzle.
- Walls are usually thicker. The drill length may not be enough. If you are making a through hole, you can go through it from two sides. If possible, make precise markings, or determine the drilling point on the other side using a magnet and a compass.
Examples of drilling holes in concrete with various tools
Concrete Hole Drilling Tools
With ordinary drills made of quick cutting or hardened steel you can drill one or two holes. Then the tool can be thrown away. Concrete requires a harder material.
This alloy is so hard that it does not grind under the influence of an abrasive. However, hardness also implies fragility. It is impossible to make a drill neck from a win, it will collapse from vibration and torque. Therefore, concrete drills are made of ordinary steel, and the victorious nozzle is soldered to the working end. The spiral for the output of sludge is made wide, the edges are not intended for cutting impact on concrete. The nozzle itself looks different than the cutting part of a conventional drill. There are no usual hooks on the edge, the winning part is made in the form of a pointed chisel.
Diamond drill bits for concrete drilling
It is irrational and impractical to perform a nozzle of diamond (even if technically grown, artificially grown). A large crystal will quickly collapse, and the cost will be too high. Therefore, for drilling concrete, steel crowns are used, on the working edge of which diamond chips are soldered.The tool is a hollow pipe. The working end has cuts for removal of sludge. The advantage of such nozzles is that the hole is neat and accurate. The disadvantages include the impossibility of centering at the beginning of drilling, and the high power of the power tool.For centering, either an axial drill bit is used, or a guide for a drill (perforator). Diamond drilling of holes in concrete requires forced cooling. The friction area is large enough, thermal overloads occur. From a high temperature, a bundle of diamond chips loses strength, and the crown begins to wear out.
Guides and cooling devices increase the complexity of the tool, but the result is worth it.
Hammer drill bits
Such nozzles are used mainly by construction crews for passage to great depths. Drilling holes in concrete for sockets can be done using simpler tools.
If you do not have a crown for drilling concrete, make a series of holes in a circle and knock out the cylinder with a jumper. However, a higher-quality niche for electrical equipment can be made an inexpensive winning crown. Another technology is to make dimensional passages in concrete walls and ceilings. The opening is drilled along the contour with the help of diamond crowns.
Drilling walls with diamond crowns. tutorial.
How to drill concrete with a drill or punch?
Everyone knows the principle of the punch. The carbide tip rubs against the blind wall of the hole, with each revolution removing another crumbled layer of concrete. The technology is trouble free, but slow.
In addition, spurious heating occurs, accelerating wear. To help the drill, the punch mechanism works. Turns are accompanied by shock movements, and the concrete is not only scraped off, but also chipped off from the bottom of the hole. The speed of passage increases significantly.
There is a flip side to the coin. When the hammer is in shock mode, it is impossible to get a smooth and accurate hole. In most cases this is not necessary. But if there is no way to hide the hole in a decorative way. It is better to use a diamond crown.
This method is especially relevant when processing low-density concrete. The puncher knocks out large pieces, violating the solidity of the material. At the same time, the crown rotating without vibration gently cuts a hole with smooth walls.
Well, if there is a choice of tool. What if a simple drill is available? A large number of large holes cannot be drilled. But you can make a hole for the picture on the wall.You will need a drill with a winning tip and a punch (jumper).
A drill makes a passage until it starts spinning idle. Then a punch is inserted into the hole, several sharp blows are applied with a hammer, and chips appear at the bottom of the hole. With the help of a drill, the crumbled surface is traversed for a certain distance, and the cycle will be repeated.
As a result, with little effort (but for a long time) you get a more or less decent hole for the dowel.
Drilling holes in concrete with a drill, master’s advice.
Fastening to concrete using non-standard methods
Self-tapping screws for concrete without drilling are used when it is impossible to use a classic pair. A drill bit / dowel. If the concrete is old, loose or too thin, it is necessary to drill a hole of small diameter (without using a hammer drill), and screw in a special configuration screw (screw). Such screws are widely used in aerated concrete walls.
If the surface, on the contrary, is especially durable, special nails for concrete without drilling are driven into it. This fixture is known for a long time, under the name “steel expansion bolt shields”. Clogged with a sharp single blow. No hole is required; retention occurs due to wedging of the monolith. For convenience and safety, you can use special devices. There is no special aesthetics in such fasteners, but for technological installation this is a practical solution.