How to make a hole in metal. How to make a hole in hardened steel without drilling. How to drill holes in large diameter metal

Today everyone has home master available essential tool for metal cutting, drilling, stripping. But what if you need to drill a large hole? After all, the maximum cross section of a conventional drill for a hand-held electric drill is only 20 mm.

Tools for drilling large holes

There are several ways to drill a hole with a diameter of more than 20 mm. For this, special devices are used:

Cone drill. A large number of holes of the same size cannot be drilled. But for home use quite acceptable. The maximum section is up to 40 mm. The thickness of the processed metal is 5-6 mm.
Cone step drill. It is more convenient to use, since each of its steps is formed through a smooth spiral transition. When drilling, this makes it easy to track the actual diameter of the hole. With it, you can drill a circle up to 40 mm in diameter on metal up to 6 mm thick.
Bimetal crowns - suitable for preparing holes up to 109 mm in steel products up to 5 mm thick. When working, it is strongly recommended to use specialized lubricants and coolants, which will ensure the maximum operational life of the cutting tool. Also, an adapter is required to install the device on an electric drill. On average, 5-20 openings can be drilled with a bimetallic crown, depending on its quality, which, accordingly, is reflected in the cost.

How can you drill a large hole at no extra cost?

For this method, you will need a small-section drill (5-6 mm is enough), as well as a milling cutter or a used grinding wheel (corresponding to or slightly smaller than the hole diameter) for the grinder. The option is more laborious, so it takes much more time.

2 circles are marked on a metal blank with a pencil:

1 - for the future hole.
2 - depends on the cross section of the drill, that is, when using a 6 mm tool, the diameter of the intended circle will be 6 mm less than the previous one.

On the 2nd circle, it is necessary to punch 2 places in opposite places and drill holes with a 6 mm drill. From the received openings along the intended line, you need to retreat about 3 mm and again mark the places for drilling. Holes are drilled along the contour of the entire circle. If necessary, the remaining sections can be chopped with a chisel.

The hole will be jagged, so it needs to be bored out. This can be done with an electric drill with a cutter, but it is much more convenient - with a grinder using grinding abrasive wheels suitable diameter. With a grinder, you can quickly and evenly bore a hole to the required diameter.

Therefore, you should not throw away used abrasive wheels for a grinder with a diameter of even less than 45 mm - they can always come in handy on the farm.

Metalworking is carried out with a special cutting tool, with the help of machines and mechanisms. Drilling holes in metal is no easy task. This technological operation requires elementary knowledge about the material, machine tools and cutting technology. Sometimes it is difficult to choose a drill taking into account different degrees of metal hardness and choose cutting conditions.

Required Tools

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

Hand tools - a drill and drills should be chosen carefully. If there is no experience in this area, it is necessary to consult a store employee. Buying an expensive high-class drill does not always guarantee its long service life.

Compliance with the technology of obtaining holes in metal and a properly selected drill significantly increases its service life and protects against premature wear. Basic rules for operating a cutting tool:

Selection of a suitable type of gimlet for drilling metal of a certain hardness. Many manufacturers have developed entire programs by which you can choose the right tool.
Selection of cutting conditions, setting the correct rotation speed.
Properly selected feed, application of the appropriate pressure force on the cutting tool.
Cooling application. An oil-based emulsion is recommended.
Proper clamping of the material (e.g. in a vise).
Fixing the drill to the stand, precisely and perpendicularly.
Application of an extended set of shims when drilling through holes.

Technological process

Drilling is the process of removing small parts of the material being processed, chips, with the help of a drill. During drilling, the temperature of the workpiece rises. 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 dulls.

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

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

Drill bits with chamfer correction have a smaller bridge, due to which the cutting edges are lengthened. Such drills can drill a hole without preliminary marking with a core.

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

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

Metal drilling

A feature of the drills is the presence of a sharp edge that allows you to perform mechanical processing of the 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 °. Drills of this type are made of HSS steel with a 5% cobalt impurity. They require cooling during operation. special drilling oil.

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 apply as little force as possible. When drilling a through hole, when the moment of exit of the cutting tool is approaching, it is necessary to reduce the feed so that the part is not pulled out, the drill is not broken, and burrs are not formed.

To obtain a conical hole in the metal, a conical drill is used. It is used as a standalone tool. They can drill a cylindrical hole, turning it into a conical one. A conical hole in the metal is made on a lathe in order to drill, bore the resulting nozzle with a cutter.

Cutting conditions

The most common mistake is too high drilling speed. The harder the material is processed, the lower the drilling speed should be applied. 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 a nice and long chip.

Depending on which tool to choose, cutting parameters are important. It is necessary to choose the right rotation speed and feed. Best Options provide desktop drilling machines, but not everywhere they can be used. It is necessary to follow the principle that the lower the speed and the lower the feed, the longer the tool will last.

For example, take stainless steel, hole 8 mm, thickness 4 mm, lotion or oil for cooling, HSS drill, drill or drilling machine: The revolutions must not exceed 400 rpm, and the feed cannot be more than 0.10 mm / turnover. In other words, you can drill at up to 400 rpm. But this speed is not optimal. Therefore, it will be optimal, for example: 170 rpm, and the feed for every 30 revolutions is 1 mm (three times less than recommended).

Cooling of 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: in technological process reaming necks. 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 under the size of 8 millimeters, then - 12 millimeters, and so each size expands to the result.

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

Drilling thin sheet

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

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

In order to cut a through groove in sheet steel, it is necessary, according to the size, to drill a successive row of holes, connecting them into a single slot with a chisel and a hammer. To do this, it is necessary to cut off the jumpers between the holes and clean the irregularities with a file.

metal pipes

In case of drilling metal pipe make sure that the workpiece is securely fixed in the vise. It is advisable to fix the drill on a vertical stand. Insert a piece of wood, identical in shape and size, into the pipe, which will save the pipe from deformation. In this case, apply a small feed.

Getting narrow nozzles

Drilling deep holes of small diameter can only be done on a special machine or a lathe using a fixture. The part is clamped in a 3-jaw chuck and checked for runout with a runout indicator. The device is attached to the 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 predetermined depth. It is problematic to use the tailstock, since the overthrow must be constantly withdrawn for chips and lubrication to exit.

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

All photos from the article

If you need to make a large diameter hole in a tree, you will have to use special tools, each of which has its own characteristics. We will consider everything possible options and tell you about their main advantages and disadvantages so that you can choose best option in accordance with the specifics of the work in a given situation.

Criteria for choosing a quality option

Below we will consider the main types of devices, but for now we will indicate the criteria that any option must meet, regardless of its modification:

Reliable manufacturing material	Of course, it is unlikely that this criterion will be determined by eye, so it is best to ask the seller for a quality certificate for the product. Unreliable counterfeit variants from China most often do not have any documents.
Quality performance	Carefully examine the product: the surface must be smooth without flaws and defects, the cutting part must be carefully sharpened. If you purchase a drill for a long wood, check whether it is even, this can be done by eye or by rolling it on a flat surface - any violations are immediately visible on it.
good packaging	Low-quality fakes are most often packed somehow, moreover, there are errors in the words. No well-known brand will allow itself a nondescript packaging, remember this.
Price	Price is also an indicator of quality, usually the most budget options short-lived, especially when it comes to drills and large-sized fixtures. After all, they are subjected to very high loads in the process.

Advice! In order to be guaranteed to purchase a quality product, whether it be, you need to contact the official representatives of a particular brand or buy products in well-known stores that care about their reputation and do not sell cheap fakes.

Metal processing is carried out not only in industrial conditions. While doing repair work by car, fabrication of structures on personal plot or carrying out repairs to the home, it is necessary to drill holes in the metal. At home, a hand drill is most often used.

This versatile tool requires some solid work skills. You can purchase or make your own machine for drilling holes in metal, but this is not a cheap pleasure.

The technology of drilling holes in metal consists in removing a thin layer of material due to simultaneous translational and rotational motion.

The main condition for high-quality and safe (for the tool) processing is holding the chuck axis in a fixed position. With the help of the machine it is easy to maintain straightness, which cannot be said when working with hand tool.

If you are not sure about the firmness of your hands (this is a normal situation for an ordinary person), mechanical assistants (jigs) are required for drilling at right angles.

Immediately make a reservation that additional conductors are required only when the thickness of the metal exceeds the diameter of the drill.

If you're making a hole in a thin steel plate, straightness doesn't matter.

There are several types of hand drill guides. Power tools are not well suited for metal work, especially when it comes to precision.

Drilling guide. Made in the form of a body, easy to hold, inside of which there are guide bushings for drills of various diameters.

The material of the sleeves is harder than the tool, so the holes do not wear out. By installing the jig exactly above the center of the intended hole, you don’t have to worry that the drill will “take away” from the given direction.

This device is especially useful when drilling perpendicular holes in pipes of small diameter, when the tip tends to slip off the cylindrical surface.

Drill guide (manual). Support device in which the tool is fixed by the neck

The sole is placed on the workpiece, holding the handle with the second hand. The drill moves strictly vertically, avoiding distortions and drifts of the drill.

The design can have an angle holder for pipes of small diameter, which makes the fixture more versatile.

With a swivel mechanism, you also get a device for drilling holes at an angle.

True, the metal cannot be drilled in this way, lateral loads will quickly break the drill.

Drill stand (semi-stationary). In fact, it is an inexpensive alternative to a drilling machine.

Drilling through holes in metal blanks is carried out with various tools using special techniques. Many specialists in the performance of engineering work have to drill holes in metal structures often. These items have high elasticity, which forces the use of special cutting devices when drilling.

Types of drills and devices for drilling in metal

Necessary devices for drilling metal products are electric and hand drills, as well as drilling machines. Working part such devices - a drill of various shapes:

spiral;
screw;
crown-shaped;
conical;
flat;
cannon;
rifle;
centering;
stepped.

Each drill has an individual marking, where the diameter of the section and the type of alloy from which it is made are indicated on the tip. To drill a hole of the required diameter, a drill bit a few tenths of a millimeter narrower is required.

Drills are also classified by length:

short;
elongated;
long.

Some materials may require a specially ground diamond-tipped drill bit. Twist drills may not be able to cope with products made of thin sheet alloys. In some cases, for drilling deep holes, the product has to be fixed in a vice, stops, conductors, corners with fasteners. This is done for safety and high quality holes.

Hole drilling modes in metal products

For drilling through holes in metal products, preliminary preparation for the process is extremely important. In the tool, it is necessary to correctly fix and direct the drill. It is necessary to adjust the frequency of rotation and other parameters. For products that are too strong, a low drill speed is recommended. An indicator of correct drilling should be a uniform long chip.

Hole types and drilling methods

In some work in production, the following types of holes in metal blanks are often needed:

Through. Punches metal blanks completely. It is important to protect the surface of the machine from accidental exit of the drill outside the workpiece in order to avoid damage to the drill and the occurrence of burrs on the blank. Workbenches with holes are ideal for these types of work, where it is possible to put a wooden gasket under the workpiece. Holes in thin blanks are drilled with flat drills, because the twist drill can noticeably destroy the edges of the product.
Deaf. They are carried out to the required depth, without penetrating the product through. In this case, an important point is measuring the depth, which is convenient to do by limiting the length of the drill with a sleeve stop or a drill chuck with a fixing stop. Professional machines are equipped automatic systems feed to a given depth size, which allows you to fix the depth of the drill.
Deep. This type of hole includes those drills whose length is five times the diameter. When drilling deep holes, it is necessary to periodically eliminate the resulting chips with the use of additional lubricants. It is often necessary to forcibly provide measures to cool the drill and the product itself, the temperature of which rises rapidly to too high. high performance as a result of friction. This applies to workpieces made of high-strength alloys. For deep holes, twist drills are used.
wide diameter. Drilling holes of large diameter in products of large proportions is a very responsible and time-consuming process. For such holes, cone, crown-shaped or stepped drills are used. Specialists carry out reaming at low tool speeds, trying to ensure the safety of the edges of the workpiece.
Complex shape. Sometimes it is necessary to drill through or blind holes in workpieces of different densities for internal threads. The technology has to be divided into two steps: preliminary site preparation and drilling itself.
Half. Half blanks are drilled, filling the cavities with wood. Stepped holes can be obtained by one of two techniques: reaming (passing a drill of a smaller diameter to the entire depth of the workpiece, followed by reaming with drills of a larger diameter) and reducing the diameter (drilling a hole of a larger diameter to the required depth, followed by replacing a drill of a smaller diameter). As a result, the hole is clearly centered.

Safety when drilling holes in metal workpieces

Start drilling holes in metal blanks with great care, avoiding the rapid destruction of the drill. Compliance with simple rules when drilling will ensure safety and guarantee the release of a quality product at the end of work:

On the eve of drilling, it is necessary to carefully check the fixation of all fastening devices on the machine.
You can start work in special clothes to prevent any elements from getting under the moving parts of the machine. Protect your eyes from metal shavings with special goggles.
When the drill tip enters the metal workpiece, it should already rotate at low speed to avoid dulling.
The drill should exit the drilled hole gradually, reducing the speed, but not stopping completely.
When the drill tip does not go deep into the workpiece, you will have to check the strength of the metal. When running over the surface with a file, it is possible to determine the degree of strength. If there is no roughness left on the grade, a diamond tipped drill or more solid material, and drill at low speeds.
Drills of small diameter, which are difficult to fix in the chuck, are recommended to be wrapped around the tail with brass wire to increase the diameter of the girth.
If the work is carried out with a polished workpiece, you can put a felt washer on the base of the drill to avoid damage when it comes into contact with the drill chuck.
To fix metal blanks made of polished or chrome-plated steel, fabric or leather gaskets are used.
When drilling deep holes, a small piece of compressed foam placed on the drill will blow off small metal chips. Also, the foam will make it possible to deepen the drill to the required mark in the production of blind holes.

Power electric drills must be taken into account when drilling holes in metal blanks of various hardness. Power tool manufacturers label their appliances with specifications on their body. For drills of different power, drills of the corresponding diameter are assumed.

You can entrust any, including drilling, to the specialists of Proflasermet. We ourselves will determine the required hole diameter and select the appropriate tool, of which we have a large selection. As a result, you will get the perfect solution in a short time.