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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 a special tool called a drill, which is told rotational movement(in some cases the workpiece rotates). By drilling you can get holes of 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.

Electroerosive processing method

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.

Tapered drill bits for drilling sheet metal

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.

Punching 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.

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.

Any hole, if it is made using a drill, has round shape and in order to make it square, you need to work hard with some filing tool. Let's look at how you can drill square hole in metal with minimal use of a file using the example of making a convenient and reliable tap driver.

In order to make a driver with a square hole for a tap, having a side of 10mm, you will need:
1. Metal rectangular block-blank 13mm thick.
2. Electric drill.
3. Kerner.
4. Center drill.
5. Drills for drilling metal with a diameter of 4mm and 9mm.
6. Any coolant.
7. Small triangular file.

The production of the knob is as follows:
1. Make a square of paper with a side of 6mm, mark the center on it and glue it to the workpiece at the place where the hole is drilled.

2. Place the workpiece on a suitable anvil and mark the vertices and center of the glued square on it with a core.

When the paper is removed from the surface of the workpiece, five punched marks remain on it.

3. Fix the workpiece with clamps on the surface of the workbench, having previously placed a wooden plank under it.

4. Use a centering drill to drill all five holes marked on the workpiece.

5. Finally drill four holes in the vertices of the square with a drill having a diameter of 4 mm,

remembering to cool them from time to time a small amount coolant

6. Having reduced the speed of the drill, use a 9mm diameter drill to finally drill the last, fifth hole located in the center of the square, again not forgetting to cool it from time to time.

7. Disassemble the design of the clamps. The result is a crank blank with a drilled square hole.

However, the edges of the hole turn out to be uneven and the tail part of the tap does not “fit” into it.

8. In order for the tap shank to fit completely into the hole, its edges are additionally processed with a file. It is more convenient to do this, of course, by clamping the workpiece in a vice, and the whole work takes no more than 15-20 minutes.

After processing with a file, the square hole in the workpiece becomes smooth, neat, and the tail part of the tap fits completely into it.

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 special tools punch out the corners. 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 cutter for square holes in a “floating” chuck.

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.