How to drill a hole in metal. How to drill a large hole in metal How to make holes in metal

The work of drilling holes in metal, depending on the type of holes and the properties of the metal, can be performed with different tools and using different techniques.

We want to tell you about drilling methods, tools, as well as safety precautions when performing these works.

Drilling holes in metal may be needed when repairing engineering systems, household appliances, cars, creating structures from sheet and profile steel, designing crafts from aluminum and copper, in the manufacture of circuit boards for radio equipment, and in many other cases. It is important to understand what kind of tool is needed for each type of work so that the holes are the right diameter and in a strictly intended place, and what safety measures will help to avoid injury.

Tools, fixtures, drills

The main tools for drilling are manual and electric drills, and, if possible, drilling machines. The working body of these mechanisms - a drill - can have a different shape.

There are drills:

spiral (most common);
screw;
crowns;
conical;
feathers, etc.

The production of drills of various designs is standardized by numerous GOSTs. Drills up to Ø 2 mm are not marked, up to Ø 3 mm - the section and steel grade are indicated on the shank, larger diameters may contain additional information. To obtain a hole of a certain diameter, you need to take a drill a few tenths of a millimeter smaller. The better the drill is sharpened, the smaller the difference between these diameters.

Drills differ not only in diameter, but also in length - short, elongated and long are produced. Important information is the ultimate hardness of the metal being processed. The shank of the drills can be cylindrical and conical, which should be borne in mind when selecting a drill chuck or adapter sleeve.

1. Drill with a cylindrical shank. 2. Tapered shank drill. 3. Drill with a sword for carving. 4. Center drill. 5. Drill with two diameters. 6. Center drill. 7. Conical drill. 8. Conical multi-stage drill

For some work and materials, special sharpening is required. The harder the metal being processed, the sharper the edge must be sharpened. For thin sheet metal, a conventional twist drill may not be suitable, you will need a tool with a special sharpening. Detailed recommendations for various types of drills and processed metals (thickness, hardness, hole type) are quite extensive, and we will not consider them in this article.

Various types of drill sharpening. 1. For hard steel. 2. For stainless steel. 3. For copper and copper alloys. 4. For aluminum and aluminum alloys. 5. For cast iron. 6. Bakelite

1. Standard sharpening. 2. Free sharpening. 3. Diluted sharpening. 4. Heavy sharpening. 5. Separate sharpening

To fix parts before drilling, a vice, stops, conductors, corners, clamps with bolts and other devices are used. This is not only a safety requirement, it is actually more convenient, and the holes are of better quality.

To chamfer and process the surface of the channel, they use a countersink of a cylindrical or conical shape, and to mark a point for drilling and so that the drill does not “jump off” - a hammer and a center punch.

Advice! The best drills are still considered to be those produced in the USSR - exact adherence to GOST in geometry and metal composition. German Ruko with titanium coating are also good, as well as drills from Bosch - proven quality. Good reviews about Haisser products - powerful, as a rule, with a large diameter. The Zubr drills, especially the Cobalt series, proved to be worthy.

Drilling modes

It is very important to correctly fix and guide the drill, as well as select the cutting mode.

When making holes in metal by drilling, important factors are the number of revolutions of the drill and the feed force applied to the drill, directed along its axis, providing the penetration of the drill at one revolution (mm / rev). When working with different metals and drills, different cutting conditions are recommended, and the harder the metal being processed and the larger the diameter of the drill, the lower the recommended cutting speed. An indicator of the correct mode is a beautiful, long chip.

Use the tables to choose the right mode and not dull the drill prematurely.

Feed S 0 , mm/rev	Drill diameter D, mm
	2,5	4	6	8	10	12	146	20	25	32
	Cutting speed v, m/min
*When drilling steel*
0,06	17	22	26	30	33	42	-	-	-	-
0,10	-	17	20	23	26	28	32	38	40	44
0,15	-	-	18	20	22	24	27	30	33	35
0,20	-	-	15	17	18	20	23	25	27	30
0,30	-	-	-	14	16	17	19	21	23	25
0,40	-	-	-	-	-	14	16	18	19	21
0,60	-	-	-	-	-	-	-	14	15	11
*When drilling cast iron*
0,06	18	22	25	27	29	30	32	33	34	35
0,10	-	18	20	22	23	24	26	27	28	30
0,15	-	15	17	18	19	20	22	23	25	26
0,20	-	-	15	16	17	18	19	20	21	22
0,30	-	-	13	14	15	16	17	18	19	19
0,40	-	-	-	-	14	14	15	16	16	17
0,60	-	-	-	-	-	-	13	14	15	15
0,80	-	-	-	-	-	-	-	-	-	13
*When drilling aluminum alloys*
0,06	75	-	-	-	-	-	-	-	-	-
0,10	53	70	81	92	100	-	-	-	-	-
0,15	39	53	62	69	75	81	90	-	-	-
0,20	-	43	50	56	62	67	74	82	–	–
0,30	-	-	42	48	52	56	62	68	75	-
0,40	-	-	-	40	45	48	53	59	64	69
0,60	-	-	-	-	37	39	44	48	52	56
0,80	-	-	-	-	-	-	38	42	46	54
1,00	-	-	-	-	-	-	-	-	-	42

Table 2. Correction factors

Table 3. Revolutions and feeds for various drill diameters and drilling in carbon steel

Types of holes in metal and methods for drilling them

Types of holes:

deaf;
through;
half (incomplete);
deep;
large diameter;
for internal thread.

Threaded holes require the determination of diameters with tolerances established in GOST 16093–2004. For common hardware, the calculation is given in table 5.

Table 5. The ratio of metric and inch threads, as well as the selection of the hole size for drilling

Metric thread				Inch thread				Pipe thread
Thread diameter	Thread pitch, mm	Thread hole diameter		Thread diameter	Thread pitch, mm	Thread hole diameter		Thread diameter	Thread hole diameter
Thread diameter	Thread pitch, mm	min.	Max.	Thread diameter	Thread pitch, mm	min.	Max.	Thread diameter	Thread hole diameter
M1	0,25	0,75	0,8	3/16	1,058	3,6	3,7	1/8	8,8
M1.4	0,3	1,1	1,15	1/4	1,270	5,0	5,1	1/4	11,7
M1.7	0,35	1,3	1,4	5/16	1,411	6,4	6,5	3/8	15,2
M2	0,4	1,5	1,6	3/8	1,588	7,7	7,9	1/2	18,6
M2.6	0,4	2,1	2,2	7/16	1,814	9,1	9,25	3/4	24,3
M3	0,5	2,4	2,5	1/2	2,117	10,25	10,5	1	30,5
M3.5	0,6	2,8	2,9	9/16	2,117	11,75	12,0	-	-
M4	0,7	3,2	3,4	5/8	2,309	13,25	13,5	11/4	39,2
M5	0,8	4,1	4,2	3/4	2,540	16,25	16,5	13/8	41,6
M6	1,0	4,8	5,0	7/8	2,822	19,00	19,25	11/2	45,1
M8	1,25	6,5	6,7	1	3,175	21,75	22,0	-	-
M10	1,5	8,2	8,4	11/8	3,629	24,5	24,75	-	-
M12	1,75	9,9	10,0	11/4	3,629	27,5	27,75	-	-
M14	2,0	11,5	11,75	13/8	4,233	30,5	30,5	-	-
M16	2,0	13,5	13,75	-	-	-	-	-	-
M18	2,5	15,0	15,25	11/2	4,333	33,0	33,5	-	-
M20	2,5	17,0	17,25	15/8	6,080	35,0	35,5	-	-
M22	2,6	19,0	19,25	13/4	5,080	33,5	39,0	-	-
M24	3,0	20,5	20,75	17/8	5,644	41,0	41,5	-	-

through holes

Through holes penetrate the workpiece completely, forming a passage in it. A feature of the process is the protection of the surface of the workbench or tabletop from the exit of the drill beyond the workpiece, which can damage the drill itself, as well as provide the workpiece with a “burr” - a hart. To avoid this, use the following methods:

use a workbench with a hole;
put a gasket made of wood or a “sandwich” under the part - wood + metal + wood;
put a metal bar under the part with a hole for the free passage of the drill;
reduce the feed rate at the last stage.

The latter method is mandatory when drilling holes "in place" so as not to damage closely spaced surfaces or parts.

Holes in thin sheet metal are cut with spatula drills, because the twist drill will damage the edges of the workpiece.

blind holes

Such holes are made to a certain depth and do not penetrate the workpiece through and through. There are two ways to measure depth:

limiting the length of the drill with a sleeve stop;
limiting the length of the drill with an adjustable stop chuck;
using a ruler fixed on the machine;
a combination of methods.

Some machines are equipped with an automatic feed to a given depth, after which the mechanism stops. During the drilling process, it may be necessary to stop the work several times to remove the chips.

Holes of complex shape

Holes located on the edge of the workpiece (half) can be made by connecting two workpieces or a workpiece and a gasket with faces and clamping with a vise and drilling a full hole. The gasket must be made of the same material as the workpiece being processed, otherwise the drill will “leave” in the direction of least resistance.

A through hole in the corner (shaped rolled metal) is performed by fixing the workpiece in a vice and using a wooden gasket.

It is more difficult to drill a cylindrical workpiece tangentially. The process is divided into two operations: preparation of a platform perpendicular to the hole (milling, countersinking) and drilling itself. Drilling holes in surfaces located at an angle also begins with the preparation of the site, after which a wooden gasket is inserted between the planes, forming a triangle, and a hole is drilled through the corner.

Hollow parts are drilled, filling the cavity with a cork made of wood.

Stepped holes are produced using two techniques:

Reaming. The hole is drilled to the full depth with a drill of the smallest diameter, after which it is drilled to a given depth with drills with diameters from smaller to larger. The advantage of the method is a well-centered hole.
Reducing the diameter. A hole of maximum diameter is drilled to a given depth, then the drills are changed with a successive decrease in diameter and a hole deepening. With this method, it is easier to control the depth of each step.

1. Drilling a hole. 2. Diameter reduction

Large diameter holes, annular drilling

Obtaining holes of large diameter in massive workpieces, up to 5–6 mm thick, is a laborious and costly task. Relatively small diameters - up to 30 mm (maximum 40 mm) can be obtained using cone, and preferably step-cone drills. For holes with a larger diameter (up to 100 mm), hollow bi-metal hole saws or hole saws with carbide teeth with a center drill will be required. Moreover, the craftsmen traditionally recommend Bosch in this case, especially on hard metal, such as steel.

Such annular drilling is less energy-intensive, but may be more financially costly. In addition to drills, the power of the drill and the ability to work at the lowest speeds are important. Moreover, the thicker the metal, the more you want to make a hole on the machine, and with a large number of holes in a sheet with a thickness of more than 12 mm, it is better to immediately look for such an opportunity.

In a thin-sheet blank, a large-diameter hole is obtained using narrow-toothed crowns or a milling cutter mounted on a grinder, but the edges in the latter case leave much to be desired.

Deep holes, coolant

Sometimes a deep hole is required. In theory, this is a hole whose length is five times the diameter. In practice, deep drilling is called, requiring forced periodic removal of chips and the use of coolants (cutting fluids).

In drilling, coolants are needed primarily to reduce the temperature of the drill and workpiece, which are heated by friction. Therefore, when making holes in copper, which has a high thermal conductivity and is itself capable of removing heat, coolant can be omitted. Cast iron is drilled relatively easily and without lubrication (except for high-strength ones).

In production, industrial oils, synthetic emulsions, emulsols and some hydrocarbons are used as coolants. In home workshops you can use:

technical vaseline, castor oil - for mild steels;
laundry soap - for aluminum alloys of the D16T type;
a mixture of kerosene with castor oil - for duralumin;
soapy water - for aluminum;
turpentine diluted with alcohol - for silumin.

The universal coolant can be prepared independently. To do this, you need to dissolve 200 g of soap in a bucket of water, add 5 tablespoons of machine oil, you can use it, and boil the solution until a soapy homogeneous emulsion is obtained. Some masters use lard to reduce friction.

Processed material	Coolant
Steel:
carbonaceous	Emulsion. Sulfurized oil
structural	Sulfurized oil with kerosene
instrumental	Blended oils
alloyed	Blended oils
Ductile iron	3-5% emulsion
Cast iron	Without cooling. 3-5% emulsion. Kerosene
Bronze	Without cooling. Blended oils
Zinc	Emulsion
Brass	Without cooling. 3-5% emulsion
Copper	Emulsion. Blended oils
Nickel	Emulsion
Aluminum and its alloys	Without cooling. Emulsion. Mixed oils. Kerosene
Stainless, high temperature alloys	Mixture of 50% sulfurated oil, 30% kerosene, 20% oleic acid (or 80% sulfofresol and 20% oleic acid)
Fiber, vinyl plastic, plexiglass and so on	3-5% emulsion
Textolite, getinaks	Compressed air blowing

Deep holes can be made by solid and annular drilling, and in the latter case, the central rod formed by the rotation of the crown is broken out not entirely, but in parts, weakening it with additional holes of small diameter.

Solid drilling is performed in a well-fixed workpiece with a twist drill, through the channels of which coolant is supplied. Periodically, without stopping the rotation of the drill, it is necessary to remove it and clean the cavity from chips. The work with a twist drill is carried out in stages: first, a short hole is taken and a hole is drilled, which is then deepened with a drill of the appropriate size. With a significant depth of the hole, it is advisable to use guide bushings.

With regular drilling of deep holes, it can be recommended to purchase a special machine with automatic coolant supply to the drill and precise centering.

Drilling by marking, template and jig

You can drill holes according to the markings made or without it - using a template or a jig.

Marking is done with a punch. A hammer blow marks a place for the tip of the drill. A felt-tip pen can also mark a place, but a hole is also needed so that the tip does not move from the intended point. The work is carried out in two stages: preliminary drilling, hole control, final drilling. If the drill "left" from the intended center, notches (grooves) are made with a narrow chisel that guide the tip to a given place.

To determine the center of a cylindrical workpiece, a square piece of tin is used, bent at 90 ° so that the height of one shoulder is approximately one radius. Applying a corner from different sides of the workpiece, draw a pencil along the edge. As a result, you have an area around the center. You can find the center by the theorem - the intersection of perpendiculars from two chords.

A template is needed when making a series of parts of the same type with several holes. It is convenient to use it for a pack of thin-sheet blanks connected with a clamp. This way you can get several drilled blanks at the same time. Instead of a template, a drawing or diagram is sometimes used, for example, in the manufacture of parts for radio equipment.

The conductor is used when the accuracy of maintaining the distances between the holes and the strict perpendicularity of the channel are very important. When drilling deep holes or when working with thin-walled tubes, in addition to the conductor, guides can be used to fix the position of the drill relative to the metal surface.

When working with a power tool, it is important to remember human safety and prevent premature wear of the tool and possible marriage. In this regard, we have collected some useful tips:

Before work, you need to check the fastening of all elements.
Clothing when working on a machine or with an electric drill should not be with elements that can fall under the action of rotating parts. Protect your eyes from chips with goggles.
The drill, when approaching the surface of the metal, must already rotate, otherwise it will quickly become dull.
It is necessary to remove the drill from the hole without turning off the drill, reducing the speed if possible.
If the drill does not go deep into the metal, then its hardness is lower than that of the workpiece. Increased hardness in steel can be detected by running a file over the sample - the absence of traces indicates increased hardness. In this case, the drill must be selected from a carbide with additives and work at low speeds with a small feed.
If a small diameter drill does not fit well in the chuck, wind a few turns of brass wire around its shank, increasing the gripping diameter.
If the surface of the workpiece is polished, put a felt washer on the drill to ensure that it does not scratch even when it comes into contact with the drill chuck. When fastening workpieces made of polished or chrome-plated steel, use spacers made of fabric or leather.
When making deep holes, a rectangular piece of foam placed on a drill can serve as a measuring instrument and at the same time blow off small chips while rotating.

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

However, many are sure that core drilling is a rather expensive method, economically viable only with industrial volumes. Is such a statement true? Partly. To date, you can choose from several options for tools and equipment for drilling holes in metal of large diameter without reaming. At the same time, the cost per hole will be justified even when drilling only a few holes.

Consider, what tool options for drilling through holes of large diameter in metal does the market offer. For comparison, we take a diameter of 51 mm.

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

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

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

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

Thicker metal can be drilled. In such crowns, every second or, as a rule, one of three consecutive carbide teeth is sharpened in its own way. This provides soft cutting, no vibration, reduced load on the cutting edges and, as a result, an increase in the resource of the crown. In such crowns, there is a short or long chip removal groove, almost the entire height of the wall. The first version of the crowns allows you to drill metal up to 12 mm thick, and up to 25 mm. It is this version of the tool for drilling holes in large diameter metal that is the most progressive, providing the best performance and quality. The price of such crowns is 20-30% higher than that of thin-walled ones and in absolute terms is 1880-1910 rubles, as we agreed, for a crown with a diameter of 51 mm. As elsewhere in nature, there are deviations in one direction or another up to 2 times, but, as usual, to consider builds a golden mean.

An option in which the metal is quite thick, say 10 mm, and the hole diameter is 20-25 mm can be solved. It is recommended as a drive, but you can also use an electric drill. With the mentioned machine, investments will amount to 21,164 rubles without VAT, and with a drill - 5,000 - 5,500 thousand.

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

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

Often when working with wood and materials based on it, it becomes necessary to drill an even round hole. You can use a jigsaw or a milling cutter, but such a tool is not always at hand or it is simply inconvenient to do the work with them. A wood dancer can make the task easier.

What is a wood ballerina

Circular adjustable drill "ballerina" - a device that is designed for drilling round holes of large diameter. The tool has a simple design. It is a shank with a transverse rod, on which movable carriages with cutters are fixed. The bar has markings, according to which you can set the required spread of the cutters relative to the center of the intended hole. A core drill is fixed in the middle of the shank. It serves as a centering element and a support for drilling.

In addition to designs with two cutting elements arranged symmetrically, there are ballerinas with one cutter or even three. In the latter case, they are located on the basis in the form of a disk with grooves.

Tool functionality

A high-quality ballerina is made of high-strength steel, which makes it possible to use the device in working with soft and hard woods.

This tool has an adjustable drilling diameter. This allows you to make holes of almost any diameter. The drilling range limitation depends on the size of the ballerina. Manufacturers produce fixtures with the following cutter spread limits:

from 30 to 120 mm;
from 40 to 200 mm;
from 40 to 300 mm;
from 40 to 400 mm.

The maximum drilling diameter is limited by the bar on which the cutters are attached. Minimum - shank thickness.

A ballerina drill can be used in any place where the use of an electric jigsaw or a manual router will be inconvenient. For example, it can be assembled and installed furniture, in the details of which it is necessary to drill a neat hole, given the limited space. Another example is an uneven (convex or concave) surface. It is unlikely that it will be possible to do everything evenly and accurately with a jigsaw or milling cutter. It will be difficult to control the tilt of the tool relative to the surface. The ballerina can easily cope with such a task.

Features of working with the tool

The principle of working with a circular drill is simple. A hole is drilled with a centering drill, and then cutters are included in the work. They gradually make a narrow groove, gradually cutting through the material in a circle to the full depth.

The materials used in working with the ballerina are varied: wood, fiberboard, chipboard, MDF, drywall, plastic. One thing in common - the thickness of the part should be no more than 15-20 millimeters. This parameter is limited by the length of the incisors. Usually the manufacturer indicates the maximum drilling depth on the packaging. When trying to drill through thicker material, problems with ragged edges can occur.

The use of a tool with a single cutter is characterized by runout. This is due to the lack of balance relative to the longitudinal axis of drilling. Especially the runout will be felt when cutting holes of large diameter. Cut holes with a drill at low or medium speeds. When working on a drilling machine, such problems do not arise.

Also, a laminated or veneered surface can cause inconvenience during operation. After passing through the decorative layer, drilling proceeds without problems.

A feature of the circular drill can be considered the possibility of adjusting the diameter. The distance between the cutters can be set on a scale on the bar, or more precisely with a caliper. This is convenient if you need to make a hole without gaps for a pipe or a round part.

The spacing of the incisors relative to the center is adjusted separately. It is necessary to expose the cutting parts as accurately as possible. This will save you unnecessary effort during operation and extend the life of the tool.

How to choose the right one and what to look for

Choosing a quality circular drill is quite easy. The main thing is to know the main points that you should pay attention to in the first place, but also not to lose sight of the little things.

The design, a very important point: a wood ballerina can be with one incisor or two or more. For frequent use, it is better to purchase an option with two or three cutting elements. It is easier to work with such devices and the quality of the processing performed will be at an acceptable level.

It will not be superfluous to be able to replace individual parts. Inexpensive circular drills may have a one-piece shank with a non-removable center drill and stem.

Metal, strength and ability to withstand workloads depend on its quality. High-quality tools are made of high-strength steel or alloys. The shape of the shank and holders of the cutters is machined. The bar is usually stamped and made of the same metal.

Cheaper options often use soft metal or alloys that can be brittle. Under load, parts can deform or break. Such a tool will not last long and it will also be difficult to achieve accuracy from it.

Workmanship, the main feature is the absence of backlash and distortion. All parts must be fitted to each other and securely fastened with fixing screws.

The marking of the bar of a high-quality ballerina is stamped. Sometimes divisions are highlighted with bright paint for better visibility.

Cutters, high-quality cutting elements are made of hardened tool steel. On the holders they are fixed with rivets or by soldering. Solid cutters with holders (made from the same metal) dull quickly and are not durable.

The manufacturer, when choosing any tool and consumables, preference should be given to well-known and long-established brands and brands. The most common are Topfix, Stayer, Irwin, Strum.

Purchasing an adjustable circular drill for household use, or if you need to drill a few holes, is completely justified. This eliminates the need to purchase an expensive tool that may only be needed a few times.

In such a simple way, you can make not only a round hole in hardened steel, but also a hole of any other shape without any extra effort. The chemical method will help you out and make the task easier. The method does not require expensive chemicals, all ingredients can be found in any household.

It will take

I offer a simple method for making holes in high speed steel. For work you will need:

any product made of high speed steel;
marker;
nail polish;
nail polish remover (can be replaced with white spirit or acetone. I chose the remover only because of the pleasant smell, and this is the same acetone);
cotton wool;
empty plastic container (bottle);
salt;
homemade device from a charger and two nails.

Making a hole in metal without a drill

We apply nail polish remover on cotton wool and degrease the surface of our workpiece.

We apply varnish to the desired area. Lacquer should be applied in a thick layer on both sides. Do not forget to carefully coat the ends. Leave the blank for 10-15 minutes for the varnish to dry.

On the dried surface, with a marker on both sides of the workpiece, I mark the place for the hole. I choose the place arbitrarily, now I need to show how a hole can be made in this way. For example, you need to put a regular factory rivet. The hole diameter should be slightly smaller than the rivet size.

Then, with a knife, remove the varnish inside the contour of the hole. Do this on both sides.

Pour water into a container and add 3 tablespoons of salt. The height of the water in the container should be 10 mm less than the height of the section of the workpiece covered with varnish.

I take a contraption made from a hair clipper charger and two nails. The nails will act as electrodes - I connected them to one contact. The other contact is just a bare, stripped wire. I use a 12V charger, but a regular mobile phone charger will do the job.

The stripped wire should be a plus, the electrodes should be a minus. We attach the positive wire with a clothespin to our workpiece. Then we lower the nails into the water.

You can make slots in the container to fix the position of the nails. Plugging in the charger. After switching on, the water around the electrode nails begins to bubble, and the cleaned mark under the hole turns black.

Note: to check the polarity of the wires, you need to connect the charger. If water begins to bubble around the nails, then this is a minus and you connected correctly. The appearance of bubbles in the water around the workpiece says that the minus is connected to it and it is necessary to throw the wires. The minus must always be connected to the electrodes and the plus to the workpiece to be etched!
We leave the container for one hour, 30 minutes after the start of the process, it is necessary to change the water. I turn off the charger and take out the workpiece.

A through hole was formed in the intended place. In order to make the hole diameter larger, the process can be continued. Or file uneven edges with a file.
This is how you can make the desired hole in the workpiece by etching high-speed steel with the help of the most common objects.

Metal processing is carried out not only in industrial conditions. When performing repair work on a car, manufacturing structures on a personal plot or carrying out repairs to a 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 a 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.