Drills are used to create holes or recesses in any material. This is due to the movement of the cutting edge along the axis, which at the same time rotates. In addition to making a new hole, a drill can also expand the old one that has an insufficient diameter. The process of making a hole is called drilling, expanding it - reaming. If only a dimple is done, it’s about drilling. By design, different types of drills are very different from each other. Next, consider what they are.
1. A screw drill, also called a helical drill, is most often used in everyday life. With this tool, the length of which can reach 27.5 centimeters, it is possible to drill both wood and other materials. Spiral drills with a diameter of 0.1 millimeter to 8 centimeters are produced.
2. A flat drill having the shape of a feather, hence the second name, a feather, is used for drilling large and deep holes. The cutting edge of it is made in the form of a blade. It can be made integral, together with the shank, or it can be attached using a boring bar or a special holder.
3. For deep drilling. If you have to drill a particularly deep hole, the depth of which exceeds 5 drill diameters, use a long drill with 2 screw channels. A special emulsion is flowing through these channels, cooling the instrument during operation. The channels are made either inside the drill or inside the tubes soldered to its back.
4. Drill unilateral cutting. When the hole to be made must be of particularly precise dimensions, take a drill designed for cutting only one side. It has a reference plane, and both edges for cutting are on one side of the central axis of the tool.
5. The core drill is hollow inside. Due to this design, it drills only a narrow ring in the material. This is the so-called crowns.
6. To make a center hole in the part, a special drill, called a centering bit, is used.
There are several variations of the tail section of this tool. We list them. So, the shank is:
The drill can be made from a single piece of metal (with a diameter of no more than 8 millimeters) or an alloy (with a diameter of up to 6 millimeters). It uses special steel, which has the name "high-speed". Her brands are: P9K15, P18 or P9.
If the drill diameter is more than 8 millimeters, it is made by welding. At the same time, the part that cuts is made of high-speed steel, and the shank is made of carbon steel.
When fragile and brittle materials are to be drilled, a drill equipped with carbide inserts is used. It has grooves that can be straight, beveled or screw type.
Depending on the task to be performed, the purpose of the drill differs. So, in the shape of the hole, they are divided into the following types:
1 cover with. The cheapest coating is black oxide film. It protects the tool from rust and also protects it from overheating. The life of the drill naturally increases.
2. The titanium nitride ceramic coating is very durable. It extends the life of the instrument not less than 3 times. The TiN-coated drill bit cannot be sharpened, otherwise all of its benefits will disappear.
3. Drills coated with TiAlN - titanium-aluminum nitride are even more high quality and reliable. At the same time, such a drill can work without fail in 5 times longer than an ordinary one.
4. Titanium carbonitride is considered to be of approximately the same quality, otherwise TiCN.
5. When working with high hardness materials, such as porcelain stoneware or stone, the strongest drills should be used - diamond coated. They have no equal in strength.
1. If it is necessary to make holes in non-ferrous metal, cast iron, steel, use spiral drills. By machining them in the longitudinal grooves leaves the chips formed during operation. It should be noted that the types of drills for metal differ from each other not only by the material and coating, but also by the type of shank. It can be made in the form of a cone, cylinder or hexagon.For fastening cylindrical drills need a cartridge, tapered inserted easier - right into the machine.
The quality of the drill can also be determined by eye - for this, look closely at its color. So, ordinary drills of low quality have an inconspicuous gray color.
But the black drill is more durable, which means that it was processed at the end of production with superheated steam.
The light shade of gold has a tool that was processed using tempering, relieving internal stress.
And if the drill shines brightly with gold, then it has a coating of titanium nitride. Such a drill will serve faithfully for a long time, and its friction is reduced due to coverage. Although its price is higher than that of other types of drills, but the quality more than pays for it.
2. Carbide drills. Since the metals have different density, then the drills for their processing must be used different. Such solid materials as heat-resistant steel, cast iron or non-ferrous metal, require the use of tools made of hard alloy.
3. A few words should be said about stepped type drills that appeared not so long ago. They are very convenient to drill fairly thin sheets of plastic, tin, as well as roofing materials. Holes with this can be from 0.4 to 3.6 centimeters and even more.
If you have to make small holes (no more than 1.2 centimeters in diameter) in a particle board or wooden surface, then these will cope with the usual spiral drill bit for metal. But large or demanding higher holes are drilled only with a special tool designed for working with wooden surfaces. They are made of special tool steel, carbon or alloyed. For metal, they are not suitable. There are the following types of drills for wood:
1. The spiral type drill is suitable for small and medium holes. Instead, you can take a drill for metal, but the hole will get a little worse quality.
2. Screw drill. Drill single-spiral type with a sharp edge for cutting is also called twisted. Due to the shape, similar to the auger, excess shavings are well removed from it during operation. If you need to get a deep hole with smooth edges, you can not do without a screw drill.
Above is a spiral, lower twisted drill bit on concrete.
3. A pen-type drill is suitable for producing holes with a diameter from a centimeter to 2.5 centimeters. The result is not very high quality - rough walls, approximate accuracy. But these drills can please extremely low price.
4. Crowns for wood. The drill, made in the form of a crown (ring), can be used when you have to drill a hole with a diameter of up to 10 centimeters. As a rule, there is one shank in the set, a mandrel and a centering drill. The crown is also supplied with several pieces.
5. The Forsner drill has a centering point as well as a sharp-edge cutter. Thanks to him, the cut line is accurate. For blind hole types that have clear dimensions, this tool is great. They drill soft wood, laminate and chipboard.
In order to work comfortably with surfaces such as brick, stone and concrete, you need to have a drill with a solid tip. It is made from a special alloy, and drilling is done using shock-rotational movements.
Unlike conventional drills with a cylindrical shank, the drill used in the perforator may, in addition to the cylindrical, have another shape. This, for example, SDS-top, SDS-max or SDS-plus. Drills with SDS shanks are used to work with perforators.
1. If it is necessary to make a medium or small hole in concrete, take a drill or a drill with a tip made of hard metal. The form of the tool is in the form of a screw.
At the top there is a drill for concrete, below is a drill for concrete for a puncher.
2. We drill a large hole with a crown, which has carbide teeth on the edge. In this case, we use the method of percussion drilling using a perforator. You can also use a diamond-coated instrument. We work with them either by hammerless drilling with water cooling or by dry drilling. At the nozzle inside there is a core - a cut out piece of material.
Pobedit drill bits may have different quality - it depends on the brand of this material (it will win). To drill a granite surface, it is necessary to take a drill that has plates of defeated medium or high hardness. Plates of medium softness, or soft, are suitable for soft concrete or brick. This should be taken into account when buying pobedit drills and drills.
It is more convenient to drill glass and tiles using either a crown or a tool made in the form of a spear.
1. A spear-shaped drill tip can be either pobed or made from tungsten carbide. In addition, there are annular diamond-coated drills. If you do not have a special tool at hand, you can take a drill to work on concrete, only sharp. And we must work carefully - because this drill has a different shape.
A spear-shaped drill on ceramic tiles, and below that a diamond drill bit.
2. But a crown on glass or ceramic tile looks about the same as a crown for concrete work, but it does not have teeth, but only dusting.
3. The tile can be drilled with special ballerinas. They will be useful if you need to make a big hole. Drill carefully, from the inside of the tile, turning the drill speed to the minimum.
Perhaps, the drill classification will be incomplete, if not to mention universal drills. Finishing rooms, such a tool can work on almost all surfaces. Brick with concrete, tile, wood with plastic, aluminum, steel - the universal drill will cope with all this. He has a clever sharpening, which, by the way, is also called universal.