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Concrete crown: an effective solution to repair issues
Recently, not only life has become more comfortable, but also such a troublesome process as repairs, which is compared to a flood or fire. Probably, the crumbs and concrete dust that fill the room while making holes in the walls really have something to do with a natural disaster. All this is in the recent past. Modern tools, including a concrete crown, have made the drilling process much more technologically advanced.
Crowns speed up and simplify setting of the overhead guard for a clean and precise work
How and how to drill holesIfor socket outlets for concrete
It is necessary to make indentations in concrete quite often, including when performing electrical wiring. Furrows are made with the help of chasers... But the places for switches and sockets are prepared in a different way.
Bit for concrete - a piece of metal pipe made of tool steel
To determine the center, you first need to make a cruciform mark on the wall using a tape measure and a pencil. Then you need to outline the proposed circle, make four holes with a drill at the intersection of the circle and straight marking lines, as well as in the center. After that, you will need a special concrete cutter, that is, a crown.
It is a piece of metal pipe, one end of which has teeth made of high-strength material, and on the second there is a flange with which the device is fixed to the rotary mechanism. There is a hole in the shank for attaching a center drill, which ensures the desired direction of rotation of the bit. The drill always comes complete with a cutter. If it is necessary to make a through hole in thick walls, an extension for a concrete crown is used. It significantly expands the operational capabilities of the device.
The advent of crowns has greatly simplified the process of making holes. When performing work with a drill, followed by knocking out concrete with a chisel, not only a lot of physical strength and time is spent, but the depressions themselves are uneven.
The crown allows to create technological holes of large and small diameters
The main varieties of concrete crowns for rosettes
The cylindrical element for all crowns is the same, but depending on the material from which the cutting part is made, there are several types of crowns for sockets on concrete:
with cutting elements made of hard metal alloys;
from tungsten carbide alloys (victorious);
with diamond coating.
The way the punch works depends on the features of the cutting part. For diamond and tungsten carbide bits, the shockless drilling method is suitable, for metal bits, in which the cutting part has the shape of teeth, the impact drilling method.
The metal crown can only be used for concrete without reinforcement. The impact effect significantly reduces the service life: such crowns cannot be restored. They are used more often for domestic needs, if it is necessary to make a small number of holes.
The crown can be assembled or a single design
Tungsten carbide bits are also only suitable for unreinforced concrete. They are quite convenient to use when making holes in walls with a tiled surface.
Diamond core bits are the most common option. They have a continuous annular edge coating. They can make holes in reinforced concrete without the use of the percussion method, which sparingly affects the supports of the structure to be drilled.
Helpful advice!When buying, it should be borne in mind that it is most often necessary to use a diamond core bit using running water. It cools the cutting edge from overheating while removing cuttings and dust generated during drilling
The principle of operation of diamond core bits for concrete
Diamond bits can vary in diameter, shank connection, dimensions, quality and shape of cutting segments. Products marked "M", that is, with a soft cutting surface, are used for working with hard concrete surfaces. They are self-cleaning from dust generated during operation, which makes the drilling process more efficient.
Diamond core bits are used for drilling reinforced concrete with a non-impact method, which protects the bearing elements of structures
Depending on the size of the cylinder, the diamond core bit can have 5 cutting elements with a diameter of 6.5 cm or 32 cutting segments for a device with a caliber of 65 cm.
For standard grades of concrete, crowns with the "C" marking are used, indicating that the spraying has an average hardness. Coating "T" (hard) is used when the devices are operating at reduced speed.
Diamond core bits for drilling in concrete can work both dry and wet drilling. Nozzles designed for drilling without water supply have specially shaped holes in the cylinder body, which help to cool the edge during operation.
Diamond bits easily penetrate reinforcement. During drilling, the concrete layer collapses only under the edge; at the end of the work, a cylinder of stone remains in the bit.
Diamond core bits for concrete are equipped with brazed wide cutting segments with diamond abrasive
When making holes of considerable diameter and depth, the drilling machine can be secured with anchors. This position promotes more accurate drilling, does not create a lot of dust, prevents cylinder seizure and reduces noise. The holes for the socket boxes are often made manually.
Standard bit diameters for concrete
Holes and recesses in concrete, both for domestic and industrial purposes, may be needed not only for building outlets, but also for laying pipes, cables, etc. Therefore, the sample parameters will not be the same, which means that tools with different dimensions: with a certain diameter for socket boxes, for pipes - depending on the section, for cables - in accordance with the dimensions of the route.
An instruction is attached to each product, where the characteristics of the crown are necessarily indicated, or this information is indicated on the marking.
The crown heads have a wide range of diameters and lengths
Helpful advice!If a socket diameter unknown, you should take measurements with a caliper along the outer edge of the product and, in accordance with the obtained indicator, purchase a crown.
The drill bits for concrete can be sold separately or as a set. The purchase of the kit is advisable if the use is not episodic. The kits usually contain 5-10 crowns of various diameters, which will allow you to make a hole in any standard size if necessary. Rigid packaging and compact placement of tools in it do not cause problems during storage and help protect products from damage associated with external environmental influences.
Varieties and cost of 68 mm concrete crowns
The dimensions of the boxes for mounting sockets and switches are standard. Recesses for them are made with 68 mm concrete crowns. This is the most common option.
In carbide (victorious) options, the cutters are set at a negative angle of 7 °. This arrangement dampens the intensity of the dynamic load on the nozzle, reduces the effect of radial and end beating. This attachment can be used for rotary hammers with a capacity of 850 W and more. The SDS Plus system is used as a mount.
Crowns for concrete 68 mm are considered the most common option
A diamond core bit with a diameter of 68 mm usually has 4 sputtered segments. These fragments are made by mixing diamond chips and metal powder. The composition is pressed, as a result of which elements of the desired shape and size are formed, which are then baked. The power of the perforator for using this type of nozzle must be at least 600 W, the recommended speed is 1000-3500 rpm, the type of nozzle is SDS Plus.
The most commonly used bits with tungsten carbide spraying have a medium grain, they are recommended for working on bricks, tiles, tiles, foam concrete, hard gypsum. The optimum number of revolutions when working with such attachments is 1500 rpm.
The price of a diamond drill bit for 68 mm concrete is on average 7-10 thousand rubles. In pobeditovyh (tungsten carbide-coated) species, it is much lower - 4-6 thousand rubles. The cost of metal products is 450-600 rubles.
The punch must have a power of at least 600 W, to use nozzles with a diameter of 68 mm
Scope and methods of application of diamond core bits for concrete 72 mm
A diamond core bit with a diameter of 72 mm is also a fairly common bit. It is used when making recesses for socket outlets, junction boxes, or when laying communication pipes. Used with a drill or hammer drill. Crowns of this diameter are divided into two types:
for dry drilling;
for wet drilling.
The tips recommended for dry operation have opposite cutouts on the sides of the cylinder, which provide cooling of the cutting edge during operation. Versions without holes in the cylindrical body require the use of running water for cooling.
Diamond core bits for 72 mm concrete are used when working in non-impact mode. They can be used to drill concrete, reinforced concrete, natural and artificial stone, ceramics. The recommended power of the rotary device is 700 W and more, the rotation speed is 1500-2000 rpm. The cutting fragments of the cutters are laser welded, which further enhances the strength of the nozzle.
With the help of bits with a diameter of 72 mm, you can drill concrete, natural and artificial stone, ceramics
Helpful advice!If during operation the rotational speed of the power tool significantly slows down, do not increase the pressure on the bit.This will not improve efficiency, but will contribute to wear on the cutting edge.
Features of the use of crowns for concrete 100 mm
During construction or renovation work, it is often necessary to drill large holes, especially for water and sewer connections. In such cases, a crown with a diameter of 100 mm is used. You can purchase this hard metal cutter. It is inexpensive - 400-450 rubles. You should not be afraid when buying such a Chinese-made cutter, as in terms of performance it is not inferior to Russian counterparts.
Grinder attachments. Their characteristics. Classification by material and purpose. Cutting, roughing and grinding devices. Wall chaser nozzle. Chainsaw grinder ..
Such a crown for concrete needs to be given time to cool, to apply the impact function of power tools. A distinctive quality of this type of cutter is its rather rapid wear. When hitting the reinforcement, the cutting edge is significantly damaged, so its further use is questioned. Before starting work, you need to be sure that there are no metal elements on the way of drilling.
To drill large holes, use a 100 mm bit
Diamond core bits for drilling concrete are more durable in operation when making holes, especially for drilling large holes. If the volume of work is significant, it is worth purchasing the latter option. Even at a significantly higher price (compared to metal crowns), such a milling cutter can be more cost-effective.
Bit for concrete 110 mm: application and specificity of fastening
The diameter of metal bits does not exceed 100 mm, so for drilling holes of 110 mm or more, you need to purchase a diamond cutter.
To work with a nozzle of this size, you will need an electric drill or perforator with a power of at least 100 watts.
When working on concrete with a 110 mm crown, it is better to use water cooling. It will prevent overheating and falling off of the soldered edge.
Crowns with a diameter of 110 mm are attached using two types of adapters
Some difficulties can arise in the process of attaching the accessory to the power tool. Most of the crowns are compatible with hammer drills and drills. As for the options for large diameters (150 mm and more), some models require a special size of the connecting elements. There are two types of cartridges, which play a major role in the mounting method:
SDS-plus. They are part of the design of low-power tools, the weight of which does not exceed 5 kg.
SDS-max. They are equipped with heavier and more powerful models of rock drills.
The bit must have a suitable shank to match the type of attachment.
The industry produces adapters (adapters) that allow you to install a crown of one type on a chuck for another purpose.
To work with a 110 mm nozzle, you need a perforator with a power of at least 100 W
Important!You cannot purchase and install a 110 mm concrete crown for a hammer drill with a capacity of 800 W or less. The use of the adapter makes it possible to connect the structure, but this does not affect the operation of the engine. A large crown on a low-power power tool contributes to the inevitable overheating with the ensuing consequences.
Crowns for concrete flush mounts: manufacturers overview
There is a fairly large selection of crowns on the market. Among the confirmed high quality and good performance characteristics - Super Hard. It is an American company with offices in various regions. Nozzles up to 80 mm in diameter provide drilling in materials of various qualities, including reinforced concrete.
The crowns for hammer drills of the domestic manufacturer "Diam Almaz" are also in demand. The company manufactures nozzles of three types:
G.High speed and good performance for concrete grades M100-M300;
series S. Recommended for concrete M400-M600;
series TOP. Used when working with heavy material.
DeWalt crowns are available in all standard sizes available
The crowns manufactured by Bosh have gained popularity and confidence among consumers. They confirm the excellent German quality. Nozzles with a diameter of 68 mm are especially in demand.
The line of DeWalt crowns (American manufacturer) is represented by models of all existing standard sizes. They can drill to a depth of 80 mm. The prices of DeWalt drill bits for concrete can be attributed to the middle segment. For example, the wear-resistant popular version of the 68 mm diamond-coated nozzle will cost an average of 7,000 rubles.
Russian-made "Enkor" cutters are quite competitive. The model 48280 is especially worth highlighting. This is a diamond core bit that can be used when working with all types of concrete, including reinforced concrete, as well as drilling stone and ceramics. It is recommended to work with it in unstressed mode. The cylinder has cooling holes.
Balance of price and quality: concrete crowns "Distar"
Almost every buyer wants to purchase a quality product at the most reasonable price. These requirements are met by diamond-coated products of the Distar trademark. The company has been supplying the market with tools for 25 years that are successfully used both in everyday life and for industrial purposes.
You can use Distar crowns as attachments for different types of power tools
Diamond core bits for concrete 68, 72, 82 mm are the most demanded models. They are distinguished by a significant resource and good drilling speed. Most of this type of nozzle has holes for cooling, so there is no need to connect water. The diamond-coated segments have a specific shape that allows cuttings to be diverted, thereby clearing the drill from drilling waste that reduces the efficiency of the work.
Crowns "Distar", depending on the characteristics of the material to be drilled, are divided into three categories:
for ceramics and cermets;
for marble and granite;
for concrete and reinforced concrete.
The crowns can be used as attachments for various types of power tools with a torque: hand drills, rotary hammers, as well as stationary drilling machines.
Distar products have a universal adapter that provides quick replacement and compatibility with other equipment
You can always choose a version of the product of this manufacturer with the necessary shank, comparable to the design features of the electrical equipment used. For the SDS Max, SDS Plus concrete crown fastener made by Distar, it is possible to match the drill or hammer drill using the 1 ¼ UNC adapter and other types of adapters.
Helpful advice!When choosing an adapter, you must carefully read the information that makes up the product labeling. If it is possible to try the adapter directly when buying it in a store (you should take a power tool with you), it is better not to neglect this method of testing. It will avoid problems and ensure the full functioning of the nozzle.
Resourcediamond drill bits for concrete for socket outlets
The life of the crown depends on objective and subjective indicators. The first should include the characteristics declared by the manufacturer. They depend on the characteristics of the cutting segments and the quality of the material to be processed. For example, a bit for concrete with a diameter of 200 mm, having a saturated diamond coating, is designed for 18-20 linear meters of drilling in reinforced concrete.
The 68 mm SDS Plus diamond core bit for concrete under optimal conditions can go 14 running meters. The larger the crown diameter, the more its resource increases.It is provided by the presence of a large number of diamond-coated cutting segments.
Nominal resource, confirmed only under the conditions of correct use of the crown
Subjective reasons affecting the resource of the nozzle include the conditions and method of operation:
The use of the hammer operation of the power tool for diamond core bits will significantly reduce the service life.
Non-rigid fastening of the support post leads to a distortion of the crown, provokes runout, which adversely affects the condition of the cutting elements.
Overpressure and uneven feed can quickly damage the spray layer.
Drilling without water will cause the bit to overheat and fall off.
As a result of the use of nozzles that are not intended for drilling concrete with reinforcement, the metal can not only destroy the coating of the cutting segments, but also lead to a violation of the integrity of the crown.
Important!It is possible to renew the diamond coating on the cutting elements of the nozzle, but it is impossible to restore the shape of the cylinder - such a crown cannot be repaired.
From all of the above, we can conclude that the nominal resource determined by the manufacturer will be confirmed only under the conditions of correct operation of the tool.
Impact mode for diamond core bits significantly reduces service life
Concrete bit: how to choose the right nozzle
Even with complete information about the purchased accessory, choosing the right tool is not so easy. Quite justified and legitimate questions arise. Maybe it's wiser to take a device with a resource reserve? Is it worth overpaying for the diamond option? To match the needs and capabilities of the tool, it is worth getting acquainted with the following selection algorithm.
First of all, it is necessary to determine which material will be processed. If you need a bit on a brick, a carbide product is enough. Drilling large quantities of concrete is safer with a diamond core bit. If the presence of reinforcement in concrete is theoretically permissible, the latter option is simply necessary.
It is worth evaluating the dimensions of the planned holes and choosing a crown of a suitable diameter, having the required chuck height. A nozzle may be needed for through holes. If you plan to drill holes of different sizes, it is better to purchase a set of crowns.
It is necessary to compare the power indicators of the drive of the power tool with which the work will be performed with the size of the crown. The larger the diameter of the nozzle, the lower the speed should be. For diamond drill bits for concrete 68 mm - this is 900-1300 rpm, for a nozzle with a diameter of 230 mm - 390-450 rpm. These figures reflect the number of revolutions without load.
Bit selection is based on preliminary determination of concrete hardness, drilling method (dry or wet), hole diameters
When choosing an adapter, it is imperative to take into account the correspondence between the size of the crown and the technical parameters of the power tool. In each specific case, it is necessary to decide what exactly is most important for solving the tasks:
drilling speed indicator;
resource of work;
material, manufacturer, price;
shank length and features;
presence or absence as a prerequisite for the need to use water as a cooler, etc.
It must be understood that a tool, if used incorrectly, becomes a weapon that is most likely to harm the one who uses it. The essence of the above article is as follows: the tool must be correctly selected and applied competently. Only then will he become a person's assistant in his creative affairs.
