# Drilling square holes drill. Manufacturing a device for drilling…

## Square

The easiest way to perform a square hole in the surface is to drill round, and then manually fit a square. But, in fact, this option has one cons:

To get a truly even and neat profile, you should go the other way. apply a drill with a drilling machine.specialized drill. It will be more correct to call it a cutter, but among the people and among manufacturers this equipment was rooted precisely as a drill.

### The value of geometry in the drill

The work of the drilling drill for square holes is based on the principle of a rounded triangle of a roar. This geometric figure is as follows:

• The equilateral triangle is drawn.
• From each of its vertices, the circul is a circle with a radius equal to the length of the side.
• In a place where three new circles intersect with each other, an equilateral triangle is obtained with convex arcuate sides.

If we rotate the resulting figure with a certain deviation from a circular orbit. the so.called eccentricity. its peaks describe a trajectory that is very similar to a square. When moving, the center of the drill is not statistical, as in ordinary spiral sills, but describes a curve of four ellipsoid arches. At the same time, the central axis itself gives unchanged rotation, and the three side parts perform cyclic swinging movements. Due to this, the cutting element can disperse the holes of the square shape, and only the internal corners remain slightly rounded, in need of a little refinement. This is the only shortage of such.

### Design

The drilling nozzle consists of a shank and working part. The shank is attached in the cartridge of the drilling tool. The working part includes a cutting head with a spiral thread, as well as a special holder and a mandrel.

This element is not in the design of ordinary sills and milling. Mandrels are a necessary part of the equipment, because it:

• holds the cutter from walks, backlash;
• Contains the holes through which the accumulated chips flies;
• reduces inertia and, accordingly, reduces the load on the drill, which directly affects its service life.

## Quality definitions by color

The quality of the drill according to any material is determined primarily by its color:

• Black color has tools of increased wear resistance, since at the finish stage of manufacture they are processed by steam.
• Thermally processed products do not have internal voltage, are highly resistant to high temperatures and are not deformed when working with carbide steels. Such cords have a slightly golden hue.
• The highest quality and stronger have a bright golden color. They are covered with reducing friction titan nitride.
• The usual unprocessed gray.haired core has a minimum service life and the lowest price.

## How to drill a square hole

People are already used to the fact that the holes are drilled with a drill, and the holes were round, therefore, the holes (in the household language. “holes”) can only turn out round. And in life holes are needed of different shapes, and a skilled master, if there are appropriate tools, can make them. You just need to know how to drill a square hole.

You can make a square hole in different ways. The choice of the method depends on the material in which you need to make a hole, its thickness, the required accuracy, the presence of tools and devices, skills of the master.

The easiest way is to make a square hole in the faner using a jigsaw. In the right place, a square is drawn or any necessary figure. Then a hole is made inside the square of the square or thin drill, a saw is inserted into it, the jigsaw is collected. and the process of cutting begins. Of course, at the same time the presence of work skills in a jigsaw will not hurt.

In a tin or in thin leaf aluminum, a square can be cut into small scissors for metal with short blades. Only first, the hole should be pierced inside the square of the square, insert the sharp end of the blade there and carefully cut down the contour. Then align the plane of the part at the edges of the square with a hammer.

If aluminum is thicker than 1 mm, then you can cut the hole with a chisel. Then straighten the edges of the circuit with a hammer and carefully process with a small file. Cutting can be performed on the machine. A stamping press equipped with stamps and matrices, develop an effort sufficient for cutting holes into a part of a thickness of several millimeters.

If the material is thick, then you have to apply the drilling method. And in this case there will be several options that differ in the complexity of the technology and the tools used. You can use ordinary round core. The desired square is drawn on the workpiece, while the supply should be provided for the finish processing. The most thin holes are drilled in the corners of the conceived square. Then you need to take a drill of a slightly larger diameter, draw a square, retreating a half.diameter of the drill inward the main square. On this new contour, you need to tap tags with a step equal to the diameter of the new drill, and drill the workpiece along these marks. The jumpers between the holes are easy to cut down with a chisel, the middle will fall out. Now the contour of the resulting hole should be treated with a file.

A very accurate shape and dimensions can be obtained by laser cutting. The source of the thin laser beam with great energy is fixed on the movable head of the coordinate machine. The trajectory of the head of the head is determined by a pre.written program. Cutting a square is one of the simplest tasks, it is possible to cut out according to the most difficult lace patterns. You can cut almost any materials with a laser beam. plywood, plastic, sheet metal. On thick metal, you can draw any patterns with a beam.

It is possible to make in detail a square or even a versatile hole with straight angles with ordinary round and. To do this, by marking the future hole, it is necessary to plunge the corners with a thin drill, retreating a little from the edges of the figure, plunge the contour and the drill of a larger diameter select the metal from the middle of the contour. Then process the faces and corners of the figure with a flat file.

## Watts drill

There is a way to drill a square hole on a drilling machine equipped with a special device. The method is based on the use of the Watts drill, the shape of which in the section corresponds to the triangle rejoice.

If this cunning triangle rotates around its center, and the center will move along its circular trajectory, then the top of the triangle when moving will draw almost a square. Only the corners will be a little rounded. They must be treated with a file. The Watts drill can be installed on a lathe and drill square holes into details of any thickness. Only between the cartridge of the machine and the drill should be installed special devices.

## Selection of cutters for drilling square openings

What difficulties can arise when choosing a drill under a square hole? It would seem that no difficulties will arise at all. You just need to come to the store, and inform the seller the size and shape of the opening, which must be obtained in the end. When buying a hollow cutter, you will need to pay attention to the following technical parameters:

• Manufacturer. the devices in question are made by all modern firms, not only domestic, but also foreign. The of such drills differ depending on who is the manufacturer. The high cost of the goods is not always indicated about its quality, therefore it is necessary to choose depending on how often you plan to use the nozzle. If often, it is better to give preference to the manufacturer products Rapid. Chinese nozzles are cheaper, so for prolonged use they are not calculated
• Drill length. depends on what depth the opening must be obtained in the end. The most common mill options in length from 160 to 225 mm
• The size of the square hole. it all depends on the task. Nozzles, depending on the size of the mandrel, have the appropriate parameters. You need to understand that this is one of the main parameters. A bit of the nozzle always has a smaller diameter than the size of the mandrel
• Type of shank. it is important to pay attention to this parameter, since it will not work to fix the drill with a conical shank in the drill cartridge
• Destination. depending on which material is planned to process. steel or wood. For steel blanks, products made of highly alloy and high.speed steel are used, and for wood, nozzles made of carbon steel are produced

## Drilling square holes with a special drill

The holes of the square shape in the blanks or products made of metal and other materials can be obtained using a cutting tool called a drill for square holes. It has another name. a drill urtts. Square holes are obtained with small roundings in the corners, which are almost invisible. They are drilled, drilled and drilled in metal with black and colored thickness not more than 16 mm, wood, faner and other materials, including substances of composite origin. The operation is performed using a drill, a pen or on lathes or lingering machines. They are used in industry, agriculture and everyday life in the manufacture of products, repair and performing crafts with their own hands.

## Selection of cutters for drilling square openings

What difficulties can arise when choosing a drill under a square hole? It would seem that no difficulties will arise at all. You just need to come to the store, and inform the seller the size and shape of the opening, which must be obtained in the end. When buying a hollow cutter, you will need to pay attention to the following technical parameters:

• Manufacturer. the devices in question are made by all modern firms, not only domestic, but also foreign. The of such drills differ depending on who is the manufacturer. The high cost of the goods is not always indicated about its quality, therefore it is necessary to choose depending on how often you plan to use the nozzle. If often, it is better to give preference to the manufacturer products Rapid. Chinese nozzles are cheaper, so for prolonged use they are not calculated
• Drill length. depends on what depth the opening must be obtained in the end. The most common mill options in length from 160 to 225 mm
• The size of the square hole. it all depends on the task. Nozzles, depending on the size of the mandrel, have the appropriate parameters. You need to understand that this is one of the main parameters. A bit of the nozzle always has a smaller diameter than the size of the mandrel
• Type of shank. it is important to pay attention to this parameter, since it will not work to fix the drill with a conical shank in the drill cartridge
• Destination. depending on which material is planned to process. steel or wood. For steel blanks, products made of highly alloy and high.speed steel are used, and for wood, nozzles made of carbon steel are produced
 The size of the drill D, mm B, mm L, mm C, mm D, mm E, mm 6×6 four 45 160 115 6 19 8×8 5.7 fifty 205 135 eight 19 10×10 6.8 fifty 205 140 ten 19 12×12 9.5 70 210 140 12 19

Based on the above parameters, the drill should be selected for square openings. First, decide on the size of the required hole, as well as its width.

It is interesting!For drilling square holes in metal blanks, it is recommended to use specialized equipment. A drill can be drilled in a wooden part, but with the mandatory use of the holder.

## Features of drilling square holes in a tree

In furniture production, the connection of parts is often performed according to the Ship-Paz system. This compound involves the presence of a square profile in component parts of the grooves. To obtain holes in the wood, a special square drill is used on wood. It is a set of a fucking tool. It consists of an internal wood drill and a bite put on it. Typically, the diameter of the drill ranges from 6 to 18 millimeters. The shank usually goes with a diameter of 19 millimeters. Such sets can be installed on a dial-up-warlide machine.

## Drill or mill?

Most of the technical community believes that after all the milling. Nevertheless, manufacturers stubbornly continue to call this tool a drill for square holes, a drill Watts or a drill, the profile of which corresponds to the triangle rejoice.

Which is more correct? If you turn to the kinematics of moving such a cutting tool (for clarity, you can use the scheme shown in the rice. 1, then we can find that the metal will be removed only by a side surface, and the cutting planes will not be one, like a conventional drill, but four, which is more characteristic.

However, one rotating movement to obtain a square hole will not be enough. Simple mathematical calculations (in this article are not given) show: in order for the “drill” for a square hole to perform its function, it must be described during operation not only the main movement of rotation of the cutting edge, but also the rocking movement of the drill/milling cutter around a certain axis. Both movements should be made in mutually opposite directions.

Figure 1. triangle reinforced: a). construction; b) the rotation sequence to obtain a square hole.

The angular speed of both rotations is determined quite simply. If for parameter F, take the speed of the drill shaft (or the pedorator), then for oscillatory rotations of the spindle around its own axis, the speed of 0.625F is sufficient. In this case, the spindle axis, as it were, is clamped between the working shaft and the drive wheel, forcing the drill/mill to hesitate in a clamping device with a residual speed

The more accurately resulting cutting speed of the cutter can be set using the technical characteristics of the drill/peorator, but it is clear that it will be much lower than the one for which the tool is originally designed. Therefore, obtaining a square hole will occur with less performance.

## Features of drilling square holes in a tree

In furniture production, the connection of parts is often performed according to the Ship-Paz system. This compound involves the presence of a square profile in component parts of the grooves. To obtain holes in the wood, a special square drill is used on wood. It is a set of a fucking tool. It consists of an internal wood drill and a bite put on it. Typically, the diameter of the drill ranges from 6 to 18 millimeters. The shank usually goes with a diameter of 19 millimeters. Such sets can be installed on a dial-up-warlide machine.

## The principle of action and the design of the drill urtts

The drilling of square holes with the help of the Watts drill is based on the principle of the rotational movement of the triangle reinforced along a specific eccentric trajectory. The shape of the drill does not repeat exactly the rounded triangle, but fits into its shape with its cutting edges.

The drill has this shape of the cutouts in order to remove the chips from the working area, as well as to maximize the moment of inertia of the tool. In addition, a decrease in the mass of the tool helps to reduce loads on the spindle of the metal cutting machine, and pointed edges increase the cutting capabilities of the drill.

In addition to the Uatts drill, a transition spindle will be needed to work, which will provide alternating displacement of the instrument center and set the trajectory necessary for work.

It consists of a transitional mount for connecting with a spindle of a machine, a gear crown, a drive gear and a gear of the gear, as well as swinging bushings. To use a square drill with household power tools, manufacturers produce special overhead templates with a cardan gear.

## Geometric parameters

The main geometric parameters include these indicators:

In addition, choosing a square drill, pay attention to the shank, which should correspond to the spindle of the tool or a set of devices, for its fastening. Drilling square holes must be performed after preliminary marking and melting the center of the future hole. It is recommended to start drilling at low rotation speeds, and then switch to the speed indicated in the passport data of the machine or tool.

## Device and principle of operation

It is impossible to apply a cutter/drill for square holes with the profile of the triangle. the grooves for the removal of the formed chips are needed.

### drill SQUARE HOLES Japanese form tool

Therefore (see. rice. 2) the profile of the working part of the tool is the above figure, from which three half.ellips. At the same time, three goals are realized: the moment of inertia of the drill, the load on the spindle, and the cutting ability of the milling cutter is reduced.

Figure 2. actual profile of the working part of the tool

The design of the tool is as follows. Actually, the working part includes the working surface, which is carried out by the removal of metal and the grooves dropping chips. Frases-crush are made for square steel holes U8 and hardened to solid HRC 52 56. Under particularly difficult operating conditions, products made of alloy steel X12 with solid steel HRC 56 60 are used. With normal supply of coolant and due to relatively low temperatures in the processing zone, the resistance of the tool is high.

A more complex design has a transition spindle. He includes:

• Frame.
• Rostish crown.
• The seat for the main spindle (if the tool is installed in the instrumental head of a metal cutting machine, then the adapter has the form of a cone cone).
• Drive gear.
• The main spindle.
• Gear gear with a gear crown.
• Swinging sleeve.

For household appliances, milling/core manufacturers for square holes offer overhead frames that are connected by a cardan gear with the cartridge, and communicate eccentric movements to the cutting tool. The thickness of this frame determines the depth of the resulting hole.

To connect the device with the cartridge of the machine, a special adapter is also necessary. It consists of:

• Corps.
• Floating shank.
• Swinging ring.
• Interchangeable sleeve for cartridges of different metalworking machines.
• Fasten screws.
• Support balls.

For the practical application of the tool under consideration, it is enough to give the spindle of the main equipment the supply in the necessary direction. For the manufacture of square holes using such equipment, milling stretch and lathes are suitable.

## Alternative ways to produce square holes

The disadvantage of Sovers Uatts is the presence of radius arcs in the corners of the square, which is not always acceptable. In addition, the core for square holes made using a triangle rejoice cannot process the workpieces of a large thickness. In such cases, you can use electric/laser technologies, as well as. which is easier to use welding or stamping.

Set of patterns for square holes are available in the range of transverse sizes up to 70 × 70 mm in metal up to 12 16 mm thick. The kit includes:

For power exposure on the punch, you can use a hydraulic jack. The punched hole favorably differs in the purity of the resulting edges, as well as the absence of burrs. A similar tool is produced, in particular, Veritas trademark (Canada).

If there is a square hole in the steel part in the welding inverter, you can burn. For this purpose, a round hole is previously drilled in the workpiece (with a margin), then the required sizes are inserted there from the graphite of the grades of EEG or MPG, after which it is sparkled along the contour. Graphite is extracted, and a square hole remains in the product. If necessary, it can be cleaned and passed.

## Square holes drill

Device for drilling large square holes

### Сверло для сверления квадратных отверстий

There are figures with a constant width. It is the triangle reinforced. the simplest figure of constant width. will help us in the drilling of square holes.

If you move the center of this “triangle” along a certain trajectory, then its peaks will draw almost a square, and it will notice the entire area inside the resulting figure.

The boundaries of the resulting figure, with the exception of small pieces in the corners, will be strictly straight! And if you continue the segments, thereby adding the corners, it will turn out exactly the square.

In order to get the described above, the center of the triangle relate needs to be moved along the trajectory, which is a gluing of four identical arches of ellipses.

Ellipas centers are located in the vertices of the square, and the semi-shafts, dutered at an angle of 45 ° relative to the sides of the square, are equal to K (11/3)/2 and K (1-1/3)/2. where k is the length of the side of the drawn square.

• Trajectory. Ellipses arcs
• Curved corners are also arcs of ellipses with centers in the corners of the square, their semi-shafts are rotated at an angle of 45 ° relative to the sides of the square and equal to K (31)/2 and K (3-1)/2.
• The shape of the corners

The area of ​​unprofitable corners is only about 2% of the area of ​​the entire square! Now, if you make a drill in the form of a triangle Relo, then it will be possible to drill square holes with slightly rounded corners, but absolutely straight sides!

We will use the well.known design. Attach the drill tough to the triangle, placed in a square guide frame.

Relot placed in a square guide frame. The frame itself is fixed on the drill. It remains now to convey the rotation of the cartridge of the drill to the triangle rejoice.

The design helps to solve this technical problem, which you probably saw many times under the bottom of the trucks driving along the street. a cardan shaft. This program received its name in Honor Jerolamo Cardano.

Now everything is ready for drilling. Take a plywood sheet and drill a square hole!

As already mentioned, the parties will be strictly straight and only the corners are a little rounded. If necessary, they can be corrected by a file.

• Square hole
• Video about how such a hole is drilled:
• A couple of photos about industrial drilling.
• Drill for a drill.

© “Encyclopedia of Technologies and Methods” Patlah in.AT. 1993-2007.

In some cases, it is necessary to get holes in the shape of a square. The usual ways are inexpensive and difficult.

The most primitive of them is reduced to preliminary drilling the hole with a diameter equal to the square of the circle, and its gradual sellers.

A tool will be required that can work without rotating the instrumental head, as well as a special adapter. It’s easier to use the so.called “square” drill (drill Watts), or, more precisely, a milling cutter.

### A little story with geometry

Back in the 15th century, the legendary Leonardo da Vinci, studying the properties of geometric shapes, drew attention to the so.called geometric objects with equal thickness.

There are an infinite number of such figures, but the simplest. in addition to a circle. is a rounded triangle, which can be formed as follows. An equilateral triangle is drawn, each of the corners of which is connected by an arc of a circle drawn from the center of the opposite side.

A feature of such a triangle will be that all its sides will have a constant width, which is equal to the length of the side of the original equilateral triangle.

Practical benefits from this fact removed. Euler, who three centuries later demonstrated the rotation of such a rounded triangle: first around his own axis, and then with some eccentricity, the benefit of the cardan mechanism of the science and technology of that time was already known.

L7815C characteristics of connection diagram

Even further in the practical use of this figure was a German engineer f. Relo, which drew attention to the fact that the trajectory of the angles of the moving triangle in certain methods of its rotation is very close to the square.

Only directly in the corners of the square the outer surface describes the arc, however, a small radius.

In the modern technical literature, such a triangle is called a triangle Relo, although this figure has actually no longer.

A few decades will pass, and the Englishman G. Watts will come up with a device that can provide a guaranteed square trajectory for a metal.cutting tool. The technical solution for the Watts drill was patented in 1916, and a year later, serial production of such tools began.

### Drill or mill?

Most of the technical community believes that after all the milling. Nevertheless, manufacturers stubbornly continue to call this tool a drill for square holes, a drill Watts or a drill, the profile of which corresponds to the triangle rejoice.

Which is more correct? If you turn to the kinematics of moving such a cutting tool (for clarity, you can use the scheme shown in the rice. 1, then we can find that the metal will be removed only by a side surface, and the cutting planes will not be one, like a conventional drill, but four, which is more characteristic.

However, one rotating movement to obtain a square hole will not be enough.

Simple mathematical calculations (in this article are not given) show: in order for the “drill” for a square hole to perform its function, it must be described during operation not only the main movement of rotation of the cutting edge, but also the rocking movement of the drill/milling cutter around a certain axis. Both movements should be made in mutually opposite directions.

Figure 1. triangle reinforced: a). construction; b) the rotation sequence to obtain a square hole.

The angular speed of both rotations is determined quite simply.

If for parameter F, take the speed of the drill shaft (or the pedorator), then for oscillatory rotations of the spindle around its own axis, the speed of 0.625F is sufficient.

## Square. Discoveries Rezo and Watts

### A little story with geometry

Back in the 15th century, the legendary Leonardo da Vinci, studying the properties of geometric shapes, drew attention to the so.called geometric objects with equal thickness.

There are an infinite number of such figures, but the simplest. in addition to a circle. is a rounded triangle, which can be formed as follows. An equilateral triangle is drawn, each of the corners of which is connected by an arc of a circle drawn from the center of the opposite side.

A feature of such a triangle will be that all its sides will have a constant width, which is equal to the length of the side of the original equilateral triangle.

Practical benefits from this fact removed. Euler, who three centuries later demonstrated the rotation of such a rounded triangle: first around his own axis, and then with some eccentricity, the benefit of the cardan mechanism of the science and technology of that time was already known.

Even further in the practical use of this figure was a German engineer f. Relo, which drew attention to the fact that the trajectory of the angles of the moving triangle in certain methods of its rotation is very close to the square.

Only directly in the corners of the square the outer surface describes the arc, however, a small radius.

In the modern technical literature, such a triangle is called a triangle Relo, although this figure has actually no longer.

A few decades will pass, and the Englishman G. Watts will come up with a device that can provide a guaranteed square trajectory for a metal.cutting tool. The technical solution for the Watts drill was patented in 1916, and a year later, serial production of such tools began.

### Drill or mill?

Most of the technical community believes that after all the milling. Nevertheless, manufacturers stubbornly continue to call this tool a drill for square holes, a drill Watts or a drill, the profile of which corresponds to the triangle rejoice.

Which is more correct? If you turn to the kinematics of moving such a cutting tool (for clarity, you can use the scheme shown in the rice. 1, then we can find that the metal will be removed only by a side surface, and the cutting planes will not be one, like a conventional drill, but four, which is more characteristic.

However, one rotating movement to obtain a square hole will not be enough.

Simple mathematical calculations (in this article are not given) show: in order for the “drill” for a square hole to perform its function, it must be described during operation not only the main movement of rotation of the cutting edge, but also the rocking movement of the drill/milling cutter around a certain axis. Both movements should be made in mutually opposite directions.

Figure 1. triangle reinforced: a). construction; b) the rotation sequence to obtain a square hole.

The angular speed of both rotations is determined quite simply.

If for parameter F, take the speed of the drill shaft (or the pedorator), then for oscillatory rotations of the spindle around its own axis, the speed of 0.625F is sufficient.

In this case, the spindle axis, as it were, is clamped between the working shaft and the drive wheel, forcing the drill/mill to hesitate in a clamping device with a residual speed

The more accurately resulting cutting speed of the cutter can be set using the technical characteristics of the drill/peorator, but it is clear that it will be much lower than the one for which the tool is originally designed. Therefore, obtaining a square hole will occur with less performance.

### Device and principle of operation

It is impossible to apply a cutter/drill for square holes with the profile of the triangle. the grooves for the removal of the formed chips are needed.

Therefore (see. rice. 2) the profile of the working part of the tool is the above figure, from which three half.ellips. At the same time, three goals are realized: the moment of inertia of the drill, the load on the spindle, and the cutting ability of the milling cutter is reduced.

Figure 2. actual profile of the working part of the tool

The design of the tool is as follows. Actually, the working part includes the working surface, which is carried out by the removal of metal and the grooves dropping chips.

Frases-crush are made for square steel holes U8 and hardened to solid HRC 52 56. Under particularly difficult operating conditions, products made of alloy steel X12 with solid steel HRC 56 60 are used.

With normal supply of coolant and due to relatively low temperatures in the processing zone, the resistance of the tool is high.

A more complex design has a transition spindle. He includes:

• Frame.
• Rostish crown.
• The seat for the main spindle (if the tool is installed in the instrumental head of a metal cutting machine, then the adapter has the form of a cone cone).
• Drive gear.
• The main spindle.
• Gear gear with a gear crown.
• Swinging sleeve.

## How else can you drill square holes

Watts drill is the main, but not the only way to perform square holes. In practice, several more ways are used. Many of them have a general shortage. the same rounded internal corners, not as neat as when processing with a cutter of Watts. They need to be additionally riche. And here are these spare methods:

• Laser cutting. Gives high accuracy of drilling. But such work requires expensive complex equipment.
• Cutting in the working surface of a round hole with a standard drill. The diameter of the circle inscribed in the square of the desired sizes is taken for the guideline. After that, the square angles are formed along the pre.planned contour.
• When working with metal of small thickness, special punch with a square in the section of the base is used. Maximum size. 70x70mm, thickness. up to 20 mm. In the set, as a rule, there are several articles. In addition to the punrate, there is also a matrix, a holder ring, a limiter and a guide sleeve. For better exposure to the bark on the processed material, a hydraulic jack is used. So the holes are more even, without zazubin.
• Another method for metal is to burn a square profile of the required size using a welding inverter. To do this, you first need to purchase a square workpiece of graphite of brands of MPG or EEG size the same as the future hole will have. The circumference is placed into which the square of the graphite blank should be inserted. It is reliably fixed, and spurred around the perimeter. After that, the graphite blank is extracted, and the resulting hole is finished to a proper look.

## Drilling square holes with Kerner

If there is no Watts drill for square holes at hand, another way to get a profile of the desired shape is used. Standard cores for metal or wooden surfaces are used, as well as Kerner. a locksmith tool for marking. The essence of the method is as follows:

• The future hole is marked on the working surface.
• Points are planned in the corners of the square. Round holes are drilled along them.
• Next, you need to perform through holes around the perimeter of the marking. The inside is removed by drilling, but for this it is worth using a suitable diameter drill.
• The internal corners of the resulting square profile are modified by a file or a file.

The method is not difficult, but takes time. Nevertheless, many still use it as an alternative to the drill Wattes.

Interesting! A special mill with a triangle Ryol will make a hole of only the diameter for which it is designed. The given way can be made of square profiles of different sizes.

A square hole of the Watts with a convex triangle at the base will help make a square hole in a metal or wooden surface at the base. For work, you can apply a drill or a peorator, but with an additional equipment. the holder of the mandrel of the drill or the guide frame.