Drill a hole in the metal. Drilling metal How to punch a large hole in metal

Now drilling holes large diameter in metal is not a serious problem. The main thing is to prepare well. Let's say you need to make a hole in a corner, channel or mortgage to strengthen building structure or hang a shelf, light fixture or conduit. That is, to do this not in a workshop or workshop, but directly on site. The easiest way to drill in such conditions is to use an electric drill. But, imagine how much pressure needs to be applied to it to drill a hole with a diameter of 16 or 20 mm? The question is not rhetorical - the force will be about 40-50 kgf. This is not at all easy to achieve if the proposed hole is located above the level of the driller's shoulders. Even 10 years ago, when such a task arose, even professionals resorted to autogenous and, just imagine, drilling small holes around the circumference of a large one. Today there is a completely professional solution for this - core drilling, which ensures the production of holes of 11 quality.

However, many are sure that core drilling is a rather expensive method, economically beneficial only for industrial volumes. Is this statement true? Partly. Today, you can choose several options for tools and equipment for drilling holes in large-diameter metal without drilling. In this case, the cost per hole will be justified even when drilling only a few holes.

Let's consider What tool options for drilling large-diameter through holes in metal does the market offer?. For comparison, we take a diameter of 51 mm.

Firstly, this bimetallic crowns. We have a choice of samples from the cheapest ones, which are immediately sold in sets and cannot be accepted by us in this review for the reason that their purpose is to drill out wood, and even if they can drill through a sheet of metal, it will not be thicker than 0.5 mm . At a price of 240 rubles, products with a wall thickness of 1-1.2 mm start, often marked HSS -Co 5% and even HSS -Co 8, but judging by the fact that drilling one hole in stainless steel takes more than one such crowns, there may be no cobalt there at all. Twice as expensive bits of more decent quality, which really allow you to drill stainless steel and ordinary steel a few millimeters thick. Bimetallic crowns This level allows you to drill 5-20 holes in a steel sheet 5 mm thick. At the same time, the use of any lubricant-cooling composition ensures that the upper limit of this range is achieved. At the third stage there are bimetallic bits from world-famous brands, which are still twice as expensive, can be equipped with special devices for quick change in a drill, but the service life is not much or does not exceed the average price level.

Drilling large diameter holes in steel sheets more than 5-6 mm thick for bimetallic crowns is very difficult, although sometimes you can hear a different opinion. It is based on data on the full drilling depth of such crowns - 35-38 mm. As a rule, only sellers of bimetallic crowns, who do not have a more worthy tool in their assortment, risk advising drilling a 30 mm sheet or beam in this way. The fact is that the bimetallic crown does not have a chip removal groove, and as soon as the thickness of the metal being drilled becomes more height crown tooth, problems begin with chip removal. In addition, the body of the bimetallic crown is not entirely cylindrical in shape, which causes jamming in metal of considerable thickness.

Unlike bimetallic crowns, they provide more accurate drilling. Carbide body hole saw- turned, while the bimetallic crown is rolled from tape and welded into a ring. There are several types of carbide drill bit designs. Without delving into the types of shanks and types of fastening, we will only analyze the cutting part. The most expensive part of the crown is the carbide teeth. The quality of the material greatly influences the drilling speed, impact resistance, bit life and the ability to drill alloy steels with a high chromium content.

The second feature that you need to pay attention to is the shape of the tooth and its size. For drilling thin sheet steel, thin stainless steel and non-ferrous metals, a narrow tooth with a flat profile, slightly beveled inward, is used. Such crowns also do not have a chip removal groove, and they will not be able to drill into metal thicker than the height of their tooth. The price of such crowns is two to three times higher than that of bimetallic crowns, depending on the design of their body, they can be designed or. Since these are professional samples, at present their counterfeits are rare, and almost all samples found on the market are of acceptable quality, but excellent quality ones should be chosen from manufacturers specializing in these products.

Thicker metal can be drilled. In such crowns, every second or, as a rule, one of three consecutive carbide teeth is sharpened in its own way. This ensures soft cutting, absence of vibration, reduced load on the cutting edges and, as a result, increased bit life. Such crowns have a short or long chip removal groove that extends almost the entire height of the wall. The first version of the crowns allows you to drill metal up to 12 mm thick, and up to 25 mm thick. It is this version of the tool for drilling holes in large-diameter metal that is the most progressive, providing the best performance and quality. The price of such crowns is 20-30% higher than that of thin-walled ones and in absolute value is 1880 - 1910 rubles, as we agreed, for a crown with a diameter of 51 mm. As everywhere in nature, there are deviations in one direction or another up to 2 times, but, as usual, consideration builds a golden mean.

An option in which the metal is quite thick, say 10 mm, and the hole diameter is 20-25 mm can be solved. It is recommended as a drive, but you can also use an electric drill. With the mentioned machine, the investment will be 21,164 rubles excluding VAT, and with a drill - 5,000 - 5,500 thousand.

For a hole with a diameter of 50-60 mm, with such a metal thickness, the use of a magnetic or stationary drilling machine is clearly required. A large load determines the high cost of investing in equipment, and together with a crown it will be about 56,000 rubles, or, option with magnetic drill stand and a separately purchased drill about 50,000. Drilling such holes with a drill by hand is not only difficult, but also dangerous.

Drilling hand electric drill in metal up to 5 mm thick, drilling large-diameter holes is not difficult when using both bimetallic and carbide bits. The choice of tool depends on the required accuracy. When drilling holes with a bimetallic crown, the ovality of the holes and the increase in diameter from the desired value can reach 4% or in absolute terms - 2 - 3 mm. When drilling with a carbide crown - only 0.6 - 1 mm. In addition, all of the carbide bits presented in the review, and almost all of the bits available on the market for metal, also drill stainless steel.

Drilling large holes is not a problem if you choose the right tool. For example, such work may be necessary to secure a channel or metal corner. The easiest way is to use an electric drill, but getting a hole with a diameter of, for example, 15 mm requires a lot of effort. To drill a large diameter hole in metal, special devices and core drilling technology are used.

Features of creation

When drilling, it must be taken into account that the crown or stepped cone nozzle must be selected in such a way that it has a smaller diameter than the hole being created.

Using various instruments it is also necessary to take into account their characteristics. For example, when drilling with conical products, smooth edges are obtained.

Drill accessories

There are several accessories for drills that can make the process easier and make a large hole smooth:

Drilling jig. This device is a housing in which there are several guide bushings for drills different diameters. The material used to create the bushings is harder than drill bits, so you don't have to worry about the tool moving to the side while drilling and widening the hole.
Drill guide. This product allows you to fix the tool in such a way that it does not deviate to the side during drilling. If such a product is not available, the tool may move to the side, resulting in an uneven edge. It can also be mounted at an angle. But when drilling metal products this is usually not required.
Drill stand. A DIY product like this can be an inexpensive replacement for a drilling machine, as it allows you to carry out work more comfortably. When using a stand, a fixed tool moves along the bar using a lever. In this case, displacement is completely eliminated, since the workpiece being drilled is securely held due to the presence of a clamp.

Using these products, you can greatly facilitate the process of drilling metal products.

Feature of deep holes

To drill a deep hole in metal, it is best to use a lathe. During this process be sure to cool down. In this case, the chips must be forcibly removed. Periodically, the tool is removed from the workpiece to remove chips.

When working without specialized devices, you should not recess the nozzle more than 2/3 of its length. Water must be used for cooling during operation. If the work is done in several approaches, changing the angle is not allowed.

Features of large diameter holes

This procedure is more complex than deep drilling. Cutting work is carried out either using a crown or using a cone drill. Crowns for metal are similar to products for concrete and drywall. The only difference is the material used to create the cutting edge.

Drilling can also be carried out with standard products in several stages. To do this, first use a nozzle of small diameter. Then a larger tool is selected.

Most in a convenient way is the use of cone drills. Such devices allow you to drill a large hole in one go. To do this, the tool is simply recessed into the material.

Hassle-free drilling

During work, you can use a small section nozzle, as well as a used grinding wheel for an angle grinder. It is important to remember that it should have a smaller diameter than the hole being created.

Before carrying out work, a circle for the hole is marked on the workpiece, and the second circle will be smaller than the first by a distance equal to the diameter of the drill used. After this, 2 holes are marked in opposite places of the circle. It is necessary to retreat 3 mm from them and mark the places for drilling. Thus, drilling occurs along the entire drawn circle. If additional work is necessary, some areas will have to be processed with a chisel. This will create jagged edges that will then need to be filed down. It is important to ensure that during work the circumference does not increase, i.e. do not expand the planned diameter.

Cone drill

The described types of drills are made from tool steel. The shanks of such products can be hexagonal or cylindrical. The cutting edge removes all burrs, so the edge is smooth. The end of the drill head has a sharpened point that allows pre-drilling of the material.

Using these products you can:

create cuts with a diameter of up to 30 mm;
forget about jagged edges;
carry out boring various diameters without changing the nozzle.

Thanks to step drills, you can create cuts of various diameters in sheet steel up to 4 mm thick. Unlike a simple cone drill, when using such products, the drilled diameter is fixed.

The disadvantages include:

the need to use tools with low speeds and high torque;
sensitivity even to small distortions.

Despite these disadvantages, this attachment allows you to conveniently work with metal plates, quickly drilling circles of the desired diameter.

Metal crown

Metal processing is a complex process, so such work is usually carried out using specialized equipment. To carry out work at home, you can use core drills.

Such products allow you to make the edges round and centered. In this case, a standard drill is used for drilling. The products consist of several parts:

crown;
centering nozzle;
product shank;
screws that are necessary for fastening.

When using a core drill, the speed of work increases up to 10 times. Another advantage is the ability to accurately drill in the range from 1.2 to 15 cm.

In this case, there is no need to perform alignment during drilling. It is also worth noting that such drills have higher wear resistance compared to twist drills.

Before starting work, a centering drill is installed in the center of the circle, after which drilling is carried out. After this, the drill is retracted and the work is carried out with a crown.

Hole press

One of the common methods is punching using a special press. It happens like this:

First, the workpiece is placed on the press table and grabbed by several clamps.
The metal is then moved under the punching tool. On at this stage The material is additionally secured using a clamping ring.
On last stage and penetration occurs using a punch.

The revolver can have several nozzles of different diameters, which allows you to quickly create holes of different diameters. Such equipment is usually not used for working with metal in domestic conditions.

If you plan to do the work at home, you should choose universal tool. This will allow you to easily process metal without worrying about purchasing additional details. The video presented will introduce you in detail to the technology of the process.

Metalworking is performed with special cutting tools, using machines and mechanisms. Drilling holes in metal is not an easy task. This technological operation requires basic knowledge about the material, machines and cutting technology. Sometimes it is difficult to select a drill taking into account different degrees of metal hardness and select cutting modes.

Required Tools

Professional metal drills(eg Bosch, Makita, Metabo or Hawera) are made exclusively from HSS. Some are coated with a protective layer, which increases their wear resistance when drilling.

Hand tools - drills and drill bits should be selected carefully. If you have no experience in this area, you should seek advice from a store employee. It's not always about buying an expensive drill high class guarantees its long service life.

Compliance with hole production technology in metal and a correctly selected drill significantly increases its service life and protects against premature wear. Basic operating rules cutting tool:

Selecting the appropriate type of gimlet for drilling metal of a certain hardness. Many manufacturers have developed entire programs using which you can select the appropriate tool.
Selecting cutting modes, setting the correct rotation speed.
Correctly selected feed, application of appropriate pressure on the cutting tool.
Application of cooling. An oil-based emulsion is recommended.
Proper fastening of the material (for example, in a vice).
Attaching the drill to the stand is precise and perpendicular.
Use of an expanded set of gaskets when drilling through holes.

Technological process

Drilling is the process of removing small parts of the material being processed, chips, using a drill. During drilling, the temperature of the workpiece increases. The cutting force leads to damage, the friction force causes a change in the geometry of the cutting edge, plus high temperature, as a result the tool gradually becomes dull.

Most drills are made from high-speed steel with different cobalt content. It is very important that it is sharpened correctly: the cutting edges are of equal length, the bridge between them is located along the axis of the cutting tool.

This ensures that both edges will perform identical work during the drilling process. The drill will not have runout, the hole diameter will correspond to the size, and heating of the part and the tool will be minimized.

A drill-drill with chamfer correction has a smaller jumper, due to this the cutting edges are lengthened. With such drills you can drill a hole without preliminary marking with a core.

The choice of drills depends on the type of work performed. NWKa HSS Baildon drills are optimal for drilling:

structural steel;
cast iron;
brass;
bronze;
aluminum;
plastics;
tree.

Drilling metal

A special feature of the drills is the presence of a sharp edge, which allows mechanical processing material. They have an equal diameter along the entire length, and the blade is sharpened at an angle of 118°. The sharpening angle varies depending on the hardness of the material, for example, for alloy steel, it is 135°. This type of drill is made of HSS steel with 5% cobalt. They require cooling during operation. special oil for drilling.

In order to drill a nozzle in metal evenly and accurately, it is necessary to use a guide device - a jig.

When drilling, it is best to use as little force as possible. When drilling a through hole, when the moment of exit of the cutting tool approaches, it is necessary to reduce the feed so that the part does not tear out, the drill does not break, or burrs do not form.

A conical drill is used to produce a conical hole in metal. It is used as stand-alone instrument. They can drill a cylindrical hole, turning it into a conical one. A conical hole in the metal is made on lathe to drill, bore the resulting nozzle with a cutter.

Cutting modes

The most common mistake is Using too high a drilling speed. The more difficult the material to process, the lower the drilling speed should be used. For example, in the case of drilling an 8 mm hole in brass, the drilling speed should be 2500 rpm, for harder alloy steel - 800 rpm. The best sign of choosing the right drilling speed is nice, long chips.

Depending on which tool to choose, cutting parameters are important. It is necessary to select the correct rotation speed and feed. Best options Benchtop drilling machines provide this, but they cannot be used everywhere. It is necessary to follow the principle: the lower the speed and the lower the feed, the longer the tool will last.

For example, take stainless steel, 8mm hole, 4mm thickness, cooling lotion or oil, HSS drill bit, drill or drilling machine: The revolutions should not exceed 400 rpm, and the feed should not be more than 0.10 mm/revolution. In other words, you can drill at a speed no higher than 400 rpm. But this speed is not optimal. Therefore, it would be optimal, for example: 170 rpm, and the feed for every 30 revolutions is 1 mm (three times less than recommended).

Cooling the drill during the drilling process is very important. Use emulsions, oils, drilling sprays. Water should be avoided, as it does not have the properties of lubricating fluids, but only cools.

Large diameter holes

To the question of how to drill a large diameter hole in metal, there is only one answer: V technological process neck drilling. For example, you need to increase the neck and get a size of thirty millimeters in diameter. First, it is drilled with a tool of a smaller diameter, for example, four millimeters, then to a size of 8 millimeters, then 12 millimeters, and so each size is expanded to the result.

A large diameter neck in a product can be made on a lathe. The operation is as follows: drilling a hole, boring the neck of the desired size. As pre-drilling is required, the process can be divided into stages: small-diameter drilling, reaming with a gradual increase in drill diameter.

Drilling thin sheet metal

The peculiarity of obtaining an armhole in a thin sheet of metal is its reliable fastening. After the drill comes out to the other side, there is a danger that the sheet may suddenly jam and tear out if it was held in your hands. The best way reliable fastening the sheet is a clamp. In this case, the risk that the tin will be torn out is much less. The number of burrs formed is reduced, which will greatly facilitate the finishing of the element.

If the metal is 0.1 millimeter thick, you can make a hole without a drill by using a metal punching tool. Its design is very simple, like pliers. A punch is attached to one lever, and a matrix to the other. The principle is the same as cold stitching using a stamp.

To cut a through groove in sheet steel, you need to drill a successive row of holes according to size, connecting them into a single slot using a chisel and hammer. To do this, it is necessary to cut off the bridges between the holes and smooth out the unevenness with a file.

Metal pipes

In case of drilling metal pipe Make sure that the workpiece is securely fastened in the vise. It is advisable to mount the drill on a vertical stand. Insert a piece of wood of the same shape and size inside the pipe, which will protect the pipe from deformation. In this case, use low feed.

Getting narrow nozzles

Drilling deep holes of small diameter can only be done on a special machine or lathe using a device. The part is clamped into a 3-jaw chuck and checked for runout with an indicator. The device is mounted on a tool holder. A drill chuck with a drill is installed in the fixture. First, the hole is centered, then the nozzle is drilled to a given depth. Apply tailstock problematic, since the overflow must be constantly removed to release chips and lubricant.

To obtain vertical holes, a right angle drilling device is used. For an electric drill it is vertical stand at an angle of 90 degrees to the base. The easiest way is to use a vertical drilling machine.

To improve the basic characteristics of the metal, it is often hardened. This technology involves increasing the hardness of the product due to strong heating of the metal and its rapid cooling. In some cases, after heat treatment it is necessary to perform drilling. By increasing this characteristic, drilling hardened metal becomes more difficult. Let's take a closer look at all the features of drilling hardened steel.

Drilling a hole in hardened steel

The spread of the question of how to drill hardened steel can be associated with the fact that when using conventional technology the tool quickly becomes dull and becomes unusable. That is why you need to pay attention to the features of drilling hardened alloy. Among the features of the technology, we note the following points:

It is necessary to properly prepare the hardened workpiece.
In some cases, a special tool is required.
Coolant is being used.

If necessary, you can make a drill for hardened steel with your own hands, which requires certain equipment and skills. However, in most cases, a purchased version is used, since it will cope better with the task when cutting hardened steel.

Nuances when drilling

The technology in question has a fairly large number of features that need to be taken into account. Drilling of hardened metal is carried out taking into account the following points:

Before carrying out work, pay attention to the hardness of the surface. This parameter is used to select the most suitable drill. Hardness can be determined using a variety of technologies.
During drilling, a large amount of heat is generated. This is why rapid wear of the cutting edge occurs. In this regard, in many cases, cooling liquid is supplied to the cutting zone.
When cutting difficult-to-cut material, it is necessary to sharpen the cutting edge from time to time. For this purpose the usual sharpening machine or a special tool. Only diamond-coated wheels are suitable as an abrasive.

There are the most various methods cutting hardened steel. Some of them significantly simplify the processing. Only by taking into account all the nuances can the quality of the resulting hole be improved.

Useful drilling techniques

For working with hardened steel, the most various technologies. The most common technologies are characterized by the following features:

Surface treatment with acid. This technology is characterized by long-term use, since it takes quite a lot of time to reduce the surface hardness. Sulfuric, perchloric or other acid can be used for etching. The procedure involves creating a lip that will contain the substance used in the cutting zone. After prolonged exposure, the metal becomes softer, it will be possible to drill when using the usual version execution.
Can be used welding machine to achieve the set goal. When exposed high temperature the metal becomes softer, which greatly simplifies the procedure.
Most often, a special drill is used. There are versions on sale that can be used for processing hardened steel. In their manufacture, metal with increased resistance to wear and high temperatures is used. However, the complexity of manufacturing and some other points determine that the cost of a special tool is quite high.

In addition, to achieve this goal, a punch is often purchased. With its help you can do small hole, which will simplify further drilling.

Use of lubricants

When drilling through hardened steel, serious friction occurs. That is why it is recommended to purchase and use various lubricants. Among the features of this processing method, we note the following points:

First, the drilling area is processed. A small amount of lubricant is applied to the surface where the hole will be located.
Oil is added to the cutting edge. To process hardened steel, a small amount of the substance is required, but it must be added from time to time, since it scatters when the tool rotates.
During work, it is recommended to take breaks to cool the cutting surface and the surface being processed.

Special oil not only simplifies drilling, but also increases the service life of the tool used.

This is because oil can reduce the temperature of the cutting edge.

Drill selection

Have become quite widespread twist drills, which are represented by a vertical rod with two grooves. Due to the specific arrangement of the grooves, a cutting edge is formed. Among the features of the choice, we note the following points:

The pobedite drill bit has become quite widespread. It can be used to work with various hardened alloys. However, a surface with too high hardness cannot be processed with such a tool.
The choice is also made based on diameter. It is worth considering that it is quite difficult to obtain a large diameter hole. Execution option larger diameter costs much more due to application large quantity material during its manufacture.
Attention is also paid to the sharpening angle, the purpose of the product and the type of material used in manufacturing. For example, cobalt versions are characterized by higher resistance to high temperatures.
It is recommended to pay attention exclusively to products famous manufacturers. This is due to the fact that Chinese versions are manufactured using low-quality materials. However, such an offer is much cheaper and can be used for short-term or one-time work.
When choosing a drill, you can be guided by the markings. It can be used to determine which materials were used in production. The diameter of the hole that can be obtained when using the tool is also indicated.

In a specialized store you can find almost everything you need to carry out the work. However, the fairly high cost of the product and some other factors determine that some decide to make a drill themselves from scrap materials. Similar work can be done if you have the required tools.

Making a homemade drill

If necessary, a drill can be made from hardened steel. Among the main recommendations for carrying out such work, we note:

Rods are selected that are made from tungsten and cobalt alloys. People call this metal victorious. Compared to with a regular drill This design option is characterized by increased wear resistance.
To process the workpiece, you need to secure it in a small vice. Otherwise, the work will be quite difficult.
To sharpen such a surface, a diamond stone is required. The usual one will not withstand long-term work.
The end surface is sharpened to create a surface that resembles a flat-head screwdriver. The cutting edges are then sharpened to produce a sharp tip.

In order to reduce the degree of surface machinability, oil is added. This ensures long-term processing due to reduced friction and lower temperature.

In conclusion, we note that processing of hardened steel should be carried out exclusively when using special tools. The work requires a drilling machine, since a manual one will not allow you to get the required hole.

Metal drills are selected based on the diameters of the holes and the properties of the material being processed. As a rule, they are made from high-speed steels, such as R6M5K5, R6M5, R4M2. Carbide drills used for working with cast iron, carbon and alloy hardened steels, stainless steel, as well as other difficult-to-process materials.

The power of the electric drill must be designed to drill a hole of the required diameter. Manufacturers of power tools indicate the corresponding specifications on the product. For example, for drills with a power of 500...700 W, the maximum drilling diameter for metal is 10...13 mm.

There are blind, incomplete, and through holes. They can be used to connect parts together using bolts, studs, pins and rivets. If the hole is drilled for the purpose of threading, it is worth turning Special attention to choose the drill diameter. Due to its beating, a hole is broken in the cartridge, which must be taken into account. Approximate data are presented in the table.

To reduce breakdown, drilling is performed in two stages: first with a smaller diameter drill, and then with the main one. The same method of sequential drilling is used when it is necessary to make a hole of large diameter.

How to drill metal correctly with a drill

The peculiarity of drilling metal with a drill is that it is necessary to manually hold the tool and give it correct position, as well as provide the required cutting speed.

After marking the workpiece, you should mark the center of the future hole. This will prevent the drill from moving away from the specified point. For ease of work, the workpiece should be clamped in a bench vice or placed on a stand so that it takes a stable position. The drill is installed strictly perpendicular to the surface that needs to be drilled. This is important to avoid it breaking.

When drilling metal, you do not need to apply much pressure to the drill. On the contrary, it should decrease as you progress. This will prevent the drill from breaking and will also reduce the formation of burrs on the exit edge of the through hole. Care must be taken to remove chips. If the cutting tool is jammed, it is released by returning it to reverse rotation.

Selecting cutting mode

When using a high-speed steel tool, you can rely on the rotation speed according to the data in the table. When working with carbide drills, the permissible values are 1.5...2 times higher.

Drilling of metal products must be carried out with cooling. If it is not used, there is a high probability that the tool will lose its cutting properties due to overheating. The cleanliness of the hole surface will be quite low. An emulsion is usually used as a coolant for hard steels. At home suitable conditions machine oil. Cast iron and non-ferrous metals can be drilled without coolant.

Features of drilling deep holes

Holes are considered deep if their size is greater than five drill diameters. The peculiarity of the work here lies in the difficulties associated with cooling and chip removal. The length of the cutting part of the tool must be greater than the depth of the hole. Otherwise, the body of the part will block the screw grooves through which chips are removed and liquid for cooling and lubrication is supplied.

First, the hole is drilled with a rigid short drill to a shallow depth. This operation is necessary to set the direction and centering of the main tool. After this, a hole of the required length is made. As you progress, you need to remove metal shavings from time to time. For this purpose, use coolant, hooks, magnets, or turn the part over.