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One of the main types machining cutting of various materials used in modern technology is drilling. It is carried out using special tool, called a drill, to which is communicated rotational movement(in some cases the workpiece rotates). By drilling you can get holes various depths and diameters.

In most cases holes, obtained by drilling, have a cylindrical shape. However, the use of special tools and special processing techniques makes it possible to give them an ellipsoidal, square, curvilinear, oblong, triangular and other shapes.

Oblong holes for fastening GOST 16030 – 70
D	B		L
	1st row	2nd row	3	4	6	8	10	12	14	16	18	20	22	25	28	32	36	40	45	50	55	60	70	80	90	100	110	125
2	2.4	-	×	×	×	×
2.5	2.9	-		×	×	×	×
3	3.4	-		×	×	×	×	×
4	4.5	-			×	×	×	×	×	×
5	5.5	-				×	×	×	×	×	×
6	6.6	7					×	×	×	×	×	×
8	9	10						×	×	×	×	×	×	×	×	×	×	×
10	11	12							×	×	×	×	×	×	×	×	×	×	×
12	13	14								×	×	×	×	×	×	×	×	×	×	×
14	15	16									×	×	×	×	×	×	×	×	×	×	×
16	17	18										×	×	×	×	×	×	×	×	×	×	×
18	19	20											×	×	×	×	×	×	×	×	×	×	×
20	22	24												×	×	×	×	×	×	×	×	×	×	×
22	24	26													×	×	×	×	×	×	×	×	×	×	×
24	26	28														×	×	×	×	×	×	×	×	×	×	×
27	30	32															×	×	×	×	×	×	×	×	×	×	×
30	33	35																×	×	×	×	×	×	×	×	×	×	×
36	39	42																	×	×	×	×	×	×	×	×	×	×
42	45	48																		×	×	×	×	×	×	×	×	×
48	52	56																				×	×	×	×	×	×	×

Square holes for fastening GOST 16030 – 70
	Square size bolt headers	B		R
		1st row	2nd row
	5	5.5	-	0.5
	6	6.6	7	0.5
	8	9	-	0.8
	10	11	12	0.8
	12	13	14	1.0
	14	15	16	1.0
	16	17	18	1.2
	20	22	24	1.2
	22	24	26	1.6
	24	26	28	1.6

Laser processing

In the conditions of modern engineering and any other production, there is often a need to obtain various materials holes having a very complex shape. A method often used for this is to use a laser beam operating in a controlled thermal splitting mode.

Today, laser processing is one of the most advanced methods of forming and processing square, oblong and others holes in a wide variety of materials. This technology allows for high-quality processing, which creates conditions for its larger-scale use.

The use of laser equipment with numerical control allows not only to manufacture or process holes a variety of shapes and configurations, but also to obtain completely finished products.

In technology, electrical erosion refers to the destruction of the surface of a product or workpiece, which occurs under the influence of electrical discharges.

This processing method is most often used to change, within certain limits, the size and shape of holes previously made in metal products and workpieces. Developers of mechanical engineering products that they design are often faced with the need to manufacture holes that may be different from cylindrical. It can be square, oblong, rectangular, curved and others holes.

It is especially difficult to process them when the material itself has characteristics such as increased hardness or high viscosity. It is in these cases that electrical discharge machining is usually used.

As practice shows, it is most effective for processing products of complex configurations made of hard materials. The fact is that the use of common mechanical methods often results in increased wear of the cutting tool.

In thin sheet metal Quite often you have to do various holes cylindrical shape. This happens, for example, when you need to produce electric installation work in steel boxes, and this is often not so easy to do.

Drilling holes in thin sheet metal using conventional twist drills is not an easy task, since the tool begins to, as they say, “pick up”. This can (and often does) lead to its breakdown, as well as to the fact that the holes are of an irregular, curved shape. Cone drills and step drills cope with this task much better.

The fact is that, thanks to their specific shape, the layer of processed material is cut evenly, without so-called “picking up” and jerking. Therefore, the drilled holes have a perfectly cylindrical shape.

Depending on the exact geometric characteristics of the cutting tool, the use of drills with a conical cutting edge makes it possible to obtain resulting diameters of various sizes. If drilling conditions are particularly difficult, then experienced craftsmen Step drills are used instead of conical ones. This cutting tool allows for very precise dimensions of the resulting holes.

One of the most common technologies for sheet metal stamping is punching. For example, in such high-precision production as instrument making, a very significant number of parts are manufactured using this method. For punching square and oblong holes special equipment is used, made of high-strength materials, resistant to long-term and constant mechanical loads and does not require frequent and thorough maintenance.

Punching holes can be done both on complex mechanized equipment and on simple hand presses. Its procedure is that a workpiece is placed between the punch and the matrix, in which a hole must be punched.

Anyone can do it in a material of any density. But what if you need a square hole? Many people will find it implausible to be able to drill a square into soft, pliable wood or into a piece of durable metal. The Watts drill copes with this difficult task.

History with geometry

Even today, to obtain a square hole, craftsmen drill a round hole of the appropriate diameter and punch out the corners with special tools. This operation can be performed much faster and easier with a “square” Watts drill. The basis of its design is the Reuleaux triangle - a figure formed by the intersection of three identical circles. The radii of these circles are equal to the side of a regular triangle, and its vertices are the centers of the circles.

The figure bears the name of the German scientist Franz Reuleaux, since he was the first to study in detail the properties of the resulting triangle and apply them in his inventions. However, the geometry of the Reuleaux triangle was used in the shape of windows in the construction of the Church of Our Lady in Bruges back in the 13th century. IN early XVI century Leonardo Da Vinci depicted a “map of the world” on four triangles Reuleau. This figure appears in his manuscripts and the Madrid Codex. In the 18th century, a triangle made of equal arcs of three circles was demonstrated by the famous mathematician Leonhard Euler. In 1916, an English engineer working in the USA, Harry Watts, developed and patented a milling cutter for square holes in a “floating” cartridge.

Features of the Watts drill

The unique invention makes it possible to obtain holes of almost correct form: The corners of the square are rounded with a small radius. The raw area of ​​a square hole does not exceed 2%. Distinctive feature triangular drill Watts is that when rotated, its center describes arcuate ellipsoidal curves, and does not stand still like a traditional twist drill. With this movement, the vertices of the triangle draw a square with parallel, perfectly straight sides. The chuck for such a cutter has an original design that does not impede movement.

Drill structure for square holes

When chips are formed, the cutter must have grooves to remove them. The profile of the working part of the Watts drill is a Reuleaux triangle with three halves of ellipses cut out of it.

This design with grooves for chip removal solves 3 problems simultaneously:

1. The inertia of the drill is reduced.
2. The cutting ability of the drill is increased.

Typically, square holes are made on lathes or milling machines. The drill for square holes is fixed in the machine chuck with a special adapter. For household use square cutter Manufacturers offer overhead frames that connect to the cardan drive chuck and communicate cutting tool eccentric movements. The depth of the hole corresponds to the thickness of the frame.

Drill steel

Today, high-quality drills that work quickly and for a long time are made from high-alloy steel grades. In their composition, such alloys contain more than 10% alloying additives, such as tungsten, chromium, vanadium and molybdenum. Different percentages of elements and various methods of hardening steel form alloys that differ in level of hardness, toughness, impact load resistance, cost and other characteristics.

Metal drill bits - the most widely used consumables for electrical equipment for several reasons:

• Metal products most often require holes for fastening: threaded connection, rivets and other types of connections.
• Metal drills can also be used when working with more soft materials, for example, with wood.
• The production technology for this type of product is similar to the principles for the production of drills for various applications.

In Russia and many other countries, the greatest demand is for drills made of high-speed steel grade R6M5, which contains tungsten and molybdenum. The strength and price of products significantly increases when cobalt is added to the alloy or drills are coated with cooling titanium-nitride sputtering.

for metal products

Metal drills are used to make holes in products made of bronze, cast iron, copper, steel different brands, metal ceramics and other materials. For drilling tough, difficult-to-cut steel, high-strength products with the addition of cobalt are used. During operation, chips are discharged along two longitudinal grooves. Based on the shape of the tail, such instruments are divided into three types:

• hexagonal,
• conical,
• cylindrical.

A metal drill with a conical shank is inserted directly into the machine when used. A special chuck is required for hex and cylindrical shanks.

Definitions of quality by color

The quality of a drill for any material is determined primarily by its color:

• Tools of increased wear resistance are black in color, since they are treated with steam at the final stage of production.
• Heat-treated products have no internal stress and are highly resistant to high temperatures and do not deform when working with carbide steels. These drills have a slightly golden tint.
• The highest quality and durable ones have a bright golden color. They are coated with friction-reducing titanium nitride.
• Regular untreated drill bits gray have a minimum service life and the lowest price.

Size range

The working dimensions of metal drills are presented modern manufacturers V wide range. GOST provides for the division of such products into types in accordance with certain sizes.

Metal drills are divided into several categories:

GOSTs 4010-77, 886-77 and 10902-77 regulate the classification of drills by length and diameter.

How to choose a drill for glass or ceramics

Professional craftsmen in their collection have drills for every material: brick and concrete, metal and plastic, diamond drill for glass and ceramics. Glass is an extremely capricious material and requires the use of a high-quality and durable drill. Glass and ceramic surfaces can be machined with diamond-coated drills at the working end. The quality of such products is determined by the method of their manufacture. The thinnest and most inexpensive drills are made using the galvanic method. Stronger instruments are produced using the powder process. They are distinguished by durability and stability. Relatively inexpensive, high-strength drills with increased abrasiveness are produced using the modern vacuum method.

To drill a hole in a glass surface, you need to have good skills. This long and painstaking process is carried out smoothly and slowly at maximum speed without pressure, only with a diamond drill mounted strictly vertically. The hole must be constantly moistened with water to cool it. This action is more like scratching a hole with diamond grains.

If you have it on hand necessary tools and drills the right size, any renovation work will take place quickly and efficiently.

I think each of you made a case for your electronic craft. And when making a body, one nasty problem often arises - making a hole with a shape other than a circle. For example, square, under an LED indicator.

I used to suffer for a long time, drilling along the contour, then grinding these teeth, cursing about the fact that I sanded off too much or messed up the parallelism. In general, I have my hands full on everything related to the machining of materials. And there is nothing to be done about it. But where the hands cannot, the head must work. And we came up with a simple and effective solution.

So. You need to make a square hole in the plastic case.

First, let's mark the hole. It is better to do this using a paper template - you need to mark the corners as clearly as possible. We do this on the outside, front side! Then the corners are drilled through with a thin drill. Here it is important to take a thinner drill. The thinner the hole, the more accurate our hole will be.

Take a ruler and a sharp scalpel. Can stationery knife or whatever is at hand. The main requirement is that it must be very sharp, rigid and not loose. I do things like this with a cutter.

Using a ruler from hole to hole, exactly according to the size of our hole (no more, no less, exactly the same!) we make cuts. The deeper the better, but without fanaticism. Because the deeper you cut, the greater the chance that the blade will break off and we will kick outer surface, but this is not the same - it’s ugly. The holes here also rule because the tip of the scalpel falls into them and the edge of the cut does not go further than the hole. Markup here most important stage . It depends on him whether everything will turn out perfect the first time or whether it will have to be trimmed.

That's it, we got four pieces inside. Now we need to pick them up from the center and break inside!

The cut we made will give us a weak point at which the plastic will burst and break. And the holes at the edges will prevent the crack from going further than it should.

It took me no more than 10 minutes to pick this hole. This includes cleaning up trash and being distracted by taking photographs and searching for a scalpel or a drill.

How to drill a hole round shape, almost everyone knows, but not everyone knows about a drill for square holes. Meanwhile, you can drill a square-shaped hole both in soft wood products and in harder metal parts. To solve this problem, special tools and devices are used, the operating principle of which is based on the properties of the simplest geometric shapes.

Operating principles and design

In order to drill a square hole, a Watts drill is usually used, the design of which is based on this geometric figure, like a Reuleaux triangle. One of the most important features of such a figure, which represents the area of ​​intersection of three equal circles, is as follows: if a pair of parallel reference lines are drawn to such a triangle, then the distance between them will always be constant. Thus, if you move the center of the Reuleaux triangle along a trajectory described by four ellipsoidal arcs, its vertices will draw an almost perfect square, with only slightly rounded vertices.

The unique properties of the Reuleaux triangle made it possible to create drills for square holes. The peculiarity of using such a tool is that the axis of its rotation should not remain in place, but move along the trajectory described above. Naturally, this movement should not be hindered by the equipment cartridge. When using such a drill and the appropriate equipment, a square hole is obtained with perfectly straight and parallel sides, but with slightly rounded corners. The area of ​​such corners not processed with tools is only 2% of the area of ​​the entire square.

Making a device for drilling square holes

Using Watts drills, working on the principle of the Reuleaux triangle, you can drill square holes in metal blanks even on a regular machine that is not equipped with special attachments. In order to create a square hole in wooden part, you can also use a regular drill, but for this it needs to be equipped with additional devices.

Make a simple device that allows you to drill square holes in wooden blanks, you can follow the following recommendations.

• To start, use a sheet of plywood or wooden board small thickness, it is necessary to make the Reuleaux triangle itself, the geometric parameters of which must correspond to the diameter of the Watts drill used.
• The drill must be firmly fixed on the surface of the manufactured triangle.
• In order for the Reuleaux triangle and the drill attached to it to move along the required trajectory, it is necessary to make a wooden guide frame. In the inside of the frame you should cut a square with geometric parameters, completely corresponding to the dimensions of the hole you are going to drill.
• The frame is fixed to the drill using a special strip, and the center of the Reuleaux triangle placed in the guide frame must coincide with the axis of rotation of the power tool chuck.
• In order to impart torque to the drill for making a square hole, but at the same time not create restrictions on the movement of the tool in the transverse direction, the shank is connected to the drill chuck through a transmission mechanism operating on the principle cardan shaft truck.
• The wooden workpiece in which it is necessary to drill a square hole should be securely fixed, and it should be positioned so that the center of the future hole strictly coincides with the axis of rotation of the drill used for processing.

Having assembled such a simple device and securely fixed all the elements of its design and the workpiece being processed, you can turn on the electric drill and begin the drilling process.

As mentioned above, a square hole drilled using such a device will have absolutely straight and parallel sides, but its corner sections will be slightly rounded. Solving the problem with rounded corners is not difficult: you can refine them using a regular needle file.

It should be borne in mind that the device described above, which is not very rigid, is used for drilling square-shaped holes in wooden pieces of small thickness.

Watts drill and a square hole made with it in a metal workpiece

As a rule, problems with the formation of round holes in metal do not arise. Today you can find a huge number of drills on sale, some can be used to form a square or rectangle. To solve this problem, special devices are also used.

Drill or cutter

Square holes are often obtained by using milling cutters. This type of tool has become extremely widespread, but in some cases it is easier to get square holes in metal using drills. Let's take the following points as an example:

1. The work is rarely carried out, so you need to reduce costs by purchasing special tools. Milling cutters are much more expensive.
2. Small processing area. Geometric shape common cutters determines restrictions on their minimum size.
3. You need to get a through hole in metal with a large thickness.

In addition, cutters are installed in machines, which are expensive, but conventional equipment is not suitable for drilling. This is due to the fact that the drill must move along a certain path.

Design and principle of operation

The Watts square hole drill is based on the Reuleaux triangle shape. Among the features are:

1. The working part of the drill is formed by forming an area of ​​intersection of three equal circles of a special shape.
2. If you place several parallel reference lines near the triangles of the working part of the drill, then the distance between them will be the same.
3. During operation, the drill axis must move along a certain path, resulting in a square or rectangle.

It is worth considering that the resulting rectangle or square has slightly rounded corners. Devices for drilling Watts square holes should not limit the movement of the chuck with the drill, otherwise it will not be possible to obtain the shape in question. The operating principles and design of the recommended equipment allow you to create it yourself using scrap materials.

Alternative Methods for Making Square Holes

The production of radius arcs leads to a significant decrease in the quality of the resulting product. That is why the possibility of using other methods for obtaining a square hole is often considered:

1. Laser systems are widely used today. They can be used for processing along a given trajectory; when the beam is focused, the metal is heated, due to which the required surface is formed.
2. The stamping method has been used for a long period. It involves the use of special equipment that is capable of providing high pressure for sheet and other workpieces. The disadvantage of the method is high cost equipment, as well as the ability to obtain only shallow excavations.
3. When using gas welding, it is also possible to form rectangular shape. However, this technology is characterized by low practicality in application, and the resulting products are of low quality.

There are special sets of punches on sale that can also be used in this case. The kit is a combination of the following elements.