Today everyone has homemade Masters Available required tool For cutting metal, drilling, stripping. But what if you need to drill a hole of a large diameter? After all, the maximum cross section regular drill For manual electric drills is only 20 mm.

Fixtures for drilling big holes

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

• Cone drill. A large number of openings will fail to drill the same size. But for home use quite acceptable. Maximum section - up to 40 mm. The thickness of the processed metal is 5-6 mm.
• Cone stepped drill. More convenient to use, since each step is formed by a smooth spiral transition. When drilling, this makes it easy to track the actual diameter of the opening. With it, you can drill a circle to 40 mm in diameter on metal with a thickness of up to 6 mm.
• Bimetallic crowns are suitable for the preparation of holes up to 109 mm in steel products with a thickness of up to 5 mm. When working, it is strongly recommended to use specialized lubricating and cooling formulations, which will ensure the maximum operational resource of the cutting tool. Also, adapter is needed to install the device to the electric drill. On average, with the help of a bimetallic crown, 5-20 openings can be drilled - depending on its quality, which, accordingly, is reflected in the cost.

How can you drill a large hole without excess costs?

For this method, it will take a small cross section (5-6 mm sufficient) drill, as well as the cutter or the spent circle (corresponding or slightly less than the hole diameter) for the grinder. An option is more time-consuming, so much more time is required.

On the metal harvesting pencil is scheduled for 2 circumference:

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

On the 2nd circle, it is necessary to put 2 places in opposite places and drill holes with a drill of 6 mm. From the obtained openings on the planned line, it is necessary to retreat approximately 3 mm and put places for the drilling. The holes are drilled along the contour of the entire circumference. If necessary, the remaining areas can be filled with chisel.

The hole will be with jar, so it needs to be crowned. This can be performed by a mill with a cutter, but it is much more convenient - the grinder using the enraged abrasive circles of a suitable diameter. The grinder can be quickly and smoothly crowded the hole to the required diameter.

Therefore, it is not necessary to throw away the spent abrasive circles for the grinder with a diameter of even less than 45 mm - they can always come in handy in the farm.

Work on the drilling of holes in the metal, depending on the type of holes and properties of the metal, can be performed different tool and using various techniques. About drilling methods, tools, as well as safety techniques When performing these works, we want to tell you.

The drilling of the holes in the metal may be needed during the repair engineering systems, household appliances, car, creating structures made of sheet and profile steel, designing aluminum and copper crafts, in the manufacture of boards for radio equipment and in many other cases. It is important to understand which tool is needed for each type of work so that the holes are the desired 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 hand and electric drills, as well as, if possible, drilling machines. The working body of these mechanisms is drill - may have a different form.

Distinguish drills:

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

Production cut various design Normated numerous gtales. Up to Ø 2 mm are not labeled, up to Ø 3 mm - on the shank it is indicated by a cross section and steel brand, large diameters may contain additional information. To obtain a hole of a certain diameter, you need to take a drill for several tenth millimeters less. The better the drill is sharpened, the smaller the difference between these diameters.

Rolls differ not only with a diameter, but also length - short, extended and long. Important information It is the limiting hardness of the metal being processed. The shank rolled can be cylindrical and conical, which should be borne in mind when selecting a drilling cartridge or transition sleeve.

1. Drill with a cylindrical shank. 2. Drill with a conical shank. 3. Drill with switches for thread. 4. Center drill. 5. Drill with two diameters. 6. Centering drill. 7. Conical drill. 8. Conical multistage drill

Some works and materials require a special sharpening. The stringently the metal processed, the sharper the edge should be sharpened. For a thin metal, the usual spiral drill may not come up, you will need a tool with a special sharpening. Detailed recommendations for of different types Rolls and processed metals (thickness, hardness, type of hole) are quite extensive, and we will not consider them in this article.

Different types of drill sharpening. 1. For rigid steel. 2. for of stainless steel. 3. For copper and copper alloys. 4. For aluminum and aluminum alloys. 5. For cast iron. 6. Bakelit

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

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

To remove the champers and processing the channel surface, use the cylindrical or conical shape, and for the point of the point under drilling and the drill "not jumped" - the hammer and kerner.

Tip! Best coarse spools It is still considered to be issued in the USSR - the exact following of the GOST according to the geometry and composition of the metal. Good and German Ruko with titanium spraying, and also rolled from Bosch - proven quality. Good feedback About Haisser products - powerful, usually large diameter. A dignity showed themselves the bison, especially the Cobalt series.

Drilling modes

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

When performing holes in metal drilling important factors Are the number of revolutions of the drill and feed force attached to the drill, directed by its axis, which ensures the drill tolerance at one turn (mm / O). When working with various metals and swells, various cutting modes are recommended, and the more hard-processed metal and the larger the diameter of the drill, the smaller the recommended cutting speed. The correct mode indicator is beautiful, long chips.

Take advantage of the tables to choose the right mode and do not fasten the drill prematurely.

Table 2. Correction factors

Table 3. Turns and feed with different diameter of drill and drilling carbon steel

Types of holes in the metal and methods of their drilling

Types of holes:

• deaf;
• cross-cutting;
• half (incomplete);
• deep;
• large diameter;
• under internal thread.

Threaded holes require the definition of diameters with tolerances set in GOST 16093-2004. For widespread hardware, the calculation is shown in Table 5.

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

Through holes

Through holes permeate the workpiece completely, forming a passage in it. The peculiarity of the process is to protect the surface of the workbench or countertops from the release of the drill beyond the workpiece, which can damage both the drill itself, as well as supply the billet "Busken" - GARTA. To avoid this, the following ways are used:

• use workbench with hole;
• put under the part for a piece of wood or "sandwich" - wood + metal + tree;
• put under the part metal bar with a hole for the free passage of the drill;
• reduce the feed rate at the last stage.

The last method is required when driving holes "at the place" so as not to damage closely located surfaces or parts.

The holes in the thin metal metal are cut with perovy rods, because the spiral drill hurts the edge of the workpiece.

Deaf hole

Such holes are performed on a certain depth and do not permeate the workpiece through. You can measure the depth in two ways:

• limiting the length of the drill in the sleeve focus;
• limiting the length of the drill with a cartridge with adjustable focus;
• using a ruler fixed on the machine;
• combination of methods.

Some machines are equipped with an automatic feed system to a predetermined depth, after which the mechanism stops. In the process of drilling, you may need to stop working several times to remove the chips.

Holes of complex shape

Holes located on the edge of the workpiece (half) can be performed by connecting the edges and pressing two blanks or blanks and gasket and driving a complete hole. The gasket must be made of the same material as the workpiece being processed, otherwise the drill will "leave" in the direction of the smallest resistance.

The through hole in the corner (profile metal) is performed by fixing the workpiece in the vice and using wooden gasket.

It is more difficult to perform the drilling of a cylindrical billet by tangent. The process is divided into two operations: preparation perpendicular hole Places (milling, Zenkovka) and actually drilling. The drill of the holes in the surfaces located at an angle are also starting from the preparation of the site, after which the wooden gasket is inserted between the planes, forming a triangle, and drilled the hole through the angle.

Hollow parts are drilled by filling out the cavity of the tube from the wood.

Holes with ledges are obtained using two techniques:

1. Crew. The hole is drilled over the entire depth of the smallest diameter drill, after which it is drilled to a predetermined depth of the cooler with the diameters from smaller to more. The advantage of the method is a well-centered hole.
2. Reduce diameter. The hole of the maximum diameter is drilled on the predetermined depth, then the roller change with a sequential decrease in diameter and the recess of the hole. In this case, the method is easier to control the depth of each stage.

1. Development of the hole. 2. Reducing diameter

Large diameter holes, ring drill

Obtaining a large diameter holes in massive blanks, a thickness of up to 5-6 mm, the case is time consuming and cost. Relatively small diameters - up to 30 mm (a maximum of 40 mm) can be obtained using cones, and better step-conical swells. For holes larger diameter (up to 100 mm) We need hollow bimetallic crowns or crowns with carbide teeth with a centering drill. And the masters traditionally in this case recommended Bosch, especially on a solid metal, for example, steel.

Such an annular drilling is less energy-proof, but may be more costly financially. In addition to the roller, the power of a drill and the ability to work at the lowest revs. And the thicker metal, the stronger the hole on the machine will want to perform, and when large quantities Holes on a sheet with a thickness of more than 12 mm better to seek such an opportunity.

In a thin-plate billet, a large diameter hole is obtained using narrow-grained crowns or cutter, fixed on the "Bulgarian", but the edges in the latter case leave the best.

Deep holes, coolant

Sometimes it is required to perform a deep hole. In theory, it is a hole, the length of which is five times more diameter. In practice, deeply called drilling, requiring forced periodic removal of chips and the use of coolant (lubricating and cooling fluids).

In the coolant drilling is needed primarily to reduce the temperature of the drill and billets, which are heated by friction. Therefore, when obtaining holes in copper, which has a high thermal conductivity and itself is capable of removing heat, coolant can not be applied. Cast iron (except high-strength) is concerned relatively easily and without lubrication.

Industrial oils, synthetic emulsions, emulsols and some hydrocarbons are used in production. In domestic workshops you can use:

• technical Vaseline, castor oil - for soft steels;
• laundry soap - for aluminum alloys of type D16T;
• kerosene mixture with castor oil - for duralumin;
• soap water - for aluminum;
• skipidar, diluted with alcohol - for silumin.

Universal cooled liquid can be prepared independently. To do this, it is necessary to dissolve 200 g of soap in a bucket of water, add 5 spoons of machine oil, can be used, and boil the solution until a soapy homogeneous emulsion is obtained. Some wizards to reduce friction use pork fat.

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

The solid drilling is performed in a well-fixed billet with a spiral drill, in the channels of which is supplied. Periodically, without stopping the rotation of the drill, it is necessary to extract it and purify the cavity from the chips. The work with a spiral drill is performed in stages: first they take a short and screw the hole, which then bueys the corresponding size drill. With a significant depth of the opening, it is desirable to use guide conductor sleeves.

With regular deletion of deep holes, you can recommend the purchase of a special machine with automatic coolant feed to the drill and accurate centers.

Drilling on markup, template and conductor

You can drill holes by setting up or without it - using a template or conductor.

Marking is performed by kerner. The hammer impact is planned for the tile of drill. Feltaster, too, you can mark the place, but the hole must also be so that the tip does not move from the intended point. The work is performed in two stages: pre-drilling, control of the opening, final drilling. If the drill "left" from the planned center, a narrow chisel is made of notches (grooves), sending the edge to a specified place.

To determine the center of the cylindrical billet, use a square piece of fusions bent under 90 ° so that the height of one shoulder is approximately one radius. Applying a corner from different sides of the workpiece, swipe along the edge. As a result, you have an area around the center. You can find the center by theorem - the intersection of perpendicular from two chords.

The template is needed when performing a series of uniform parts with multiple holes. It is convenient to use it for a pack of thin-leaf blanks, connected clamps. So at the same time, you can get a few drilled blanks. Instead of a template, sometimes the drawing or scheme is used, for example, in the manufacture of parts for radio equipment.

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

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

1. Before work, you need to check the attachments of all items.
2. Clothing when working on a machine or with an electric drill should not be with elements capable of entering rotating parts. Eyes from chips protect the glasses.
3. The drill when approaching the metal surface should be rotated, otherwise it quickly fills.
4. It is necessary to remove the drill from the hole without turning off the drill, if possible, reducing turnover.
5. If the drill does not deepen into the metal, it means that its hardness is lower than that of the workpiece. Increased hardness in steel can be revealed by spending on a sample with a file - the absence of traces indicates increased hardness. In this case, the drill must be chosen from solid alloy with additives and work on low revs with a small feed.
6. If the small diameter drill is poorly fixed in the cartridge, wrap on its shank several turns of brass wire, increasing the diameter to capture.
7. If the surface of the workpiece is polished, wear the felt washer on the drill to be guaranteed not to apply scratches even when contact with the drill patron. When fixing billets from polished or chrome steel, use gaskets from fabric or skin.
8. In the manufacture of deep holes, a rectangular piece of foam plastic, planted on the drill, can serve as a meter and simultaneously, rotating, blow up a small chips.

Now the drilling of the holes for large diameter in the metal is not a serious problem. The main thing is to prepare well. Suppose you need to do a hole in the corner, a channel or mortgage to strengthen construction construction Or suspend the shelf, lamp or pipeline. That is, it is not in the conditions of the workshop or workshop, but directly at the place. The easiest way to drill in such conditions to use the electric drill. But, imagine what pressure on it should be applied 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. It is not easy to ensure that the alleged hole is located above the shoulder level of the borler. 10 years ago, if such a task occurs, even professionals resorted to autogen and, submit only to drilling small holes around the circumference of the big one. Today there is a very professional solution for this - a crown drilling that provides the production of holes of 11 qualifications.

However, many are confident that the coroned drilling is a fairly expensive method economically beneficial only under industrial volumes. Is such a statement right? Partly. To date, you can choose several options tool and equipment for drilling a hole in a large diameter metal without reassuring. At the same time, the costs of one hole will be justified even when drilling of just a few holes.

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

First, it is bimetallic crowns. Samples are presented from the cheapest, which are immediately sold by sets and cannot be taken to this review for the reason that their purpose is drilling a tree, and if they are drilled by a metal sheet, it will not be thicker 0.5 mm . At a price of 240 rubles, products with a wall thickness of 1-1.2 mm start, often there is a HSS -CO -CO label on it and even HSS -CO 8, but judging by the fact that the drilling of one hole in the stainless steel is more such such Crowns, cobalt there may be not at all. Twice as good Crowns of more decent quality, really allowing drilling a stainless steel and ordinary steel with a thickness of several millimeters. Bimetallic crowns Such a 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 and cooling composition ensures the achievement of the upper plank of this range. The third steps are bimetallic crowns worldwide famous brandswhich are still more expensive, can be equipped with special devices for quick shift in a drill, but on the resource is not much or do not exceed the average price level at all.

Drilling of high diameter holes in steel sheets More than 5-6 mm thick for bimetallic crowns is more difficult, although sometimes you can hear another opinion. It is based on data on the full depth of drilling such crowns - 35-38 mm. As a rule, only sellers of bimetallic crowns, which in the range there is no more worthy tool, risk advise to drill 30 mm sheet or beam so far. The fact is that the bimetallic crown is deprived of the chips in the groove, and as soon as the thickness of the muscles becomes greater than the height of the corton tooth, problems with the chips are taped. In addition, the housing of the bimetallic crown is not quite a cylindrical shape, it causes a stirring in the metal of solid thickness.

Unlike bimetallic crowns, provide more accurate drilling. Housing carbide ring saw - Exceived, while the bimetallic crown rolled out of the ribbon and cooked into the ring. There are several types of carbide drilling crowns. Without deepening in the types of shanks and fastening types, we will analyze only the cutting part. The most expensive part of the crown is a solid alloy teeth. From the quality of the material, the speed of drilling, stroke resistance, crown resource and the ability to drill alloyed steel with high chromium was depends.

The second feature on which attention should be paid is a shape of the tooth and its size. For drilling of thin-grained steel, fine stainless steel and non-ferrous metals, a narrow tooth with a flat profile is used, slightly bevelled inside. These crowns also do not have a chips in the groove, and the metal to drill them thicker the height of their tooth will not work. The price of such crowns is two to three times higher than that of bimetallic crowns, depending on the design of their housing, they can be intended or. Since that professional samples, Currently, their fakes are not much common, and almost all samples of acceptable quality in the market, but excellent quality It is necessary to choose from producers specializing in these products.

Thirdly metal can be drilled. In such crowns, each second or, as a rule, one of three consecutive carbide teeth is sharpened in its own way. It provides a soft cutting, lack of vibration, reducing the load on the cutting edges and, as a result, an increase in the rowing resource. In such crowns, there is a short or long, almost all over the height of the wall shabby groove. The first variant of the crown allows the metal to be drilled with a thickness of up to 12 mm, and - up to 25 mm. It is this embodiment of a tool for drilling a hole in a large diameter metal is the most progressive, providing better performance and quality. The price of such crowns is 20-30% higher than that of thin-walled and in the absolute value of 1880 - 1910 rubles, as we agreed, for the crown with a diameter of 51 mm. As well as everywhere in nature, there are deviations in one direction or another to 2 times, but, as usual, we are considering building a golden middle.

A variant at which the metal is rather thick, say 10 mm, and the diameter of the hole 20-25 mm can be solved. It is recommended that the drive is recommended, but you can use the electric drill. With the mentioned attachment machine, 21 164 rubles without VAT, and with a drill - thousand 5,000 - 5,500.

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 unambiguously required. A large load determines the greater value of investments in equipment, and together with the crown will be about 56,000 rubles, or, option with magnetic rack drilling machine and a separately acquired drill of about 50,000. Drill such holes drill with hands - the occupation is not only heavy, but also dangerous.

The drilling of a manual electric drill in metal with a thickness of up to 5 mm of a large diameter holes is not possible when using both bimetallic and carbide crowns. The tool selection is carried out depending on the required accuracy. When drilling holes with bimetallic crown, the ovality of the holes and an increase in the diameter from the desired can reach 4% or in absolute terms - 2 - 3 mm. When drilling a carbide crown - only 0.6 - 1 mm. In addition, all carbide crowns presented in the review, and almost all that are in the market of crowns for metal, drilled and stainless steel.

The metal drills are selected, based on the diameters of the holes and properties of the material being processed. As a rule, they are made of high-speed steels, such as P6M5K5, P6M5, R4M2. Carbide drills are used to work with cast iron, carbon and alloyed hardened steel, stainless steel, as well as other hard-writable materials.

The power of the electric drill must be calculated to drill the hole of the required diameter. Power tool manufacturers indicate the appropriate specifications on the product. For example, for drills with a capacity of 500 ... 700 W, the maximum diameter of the drilling in the metal is 10 ... 13 mm.

There are deaf, incomplete, as well as through holes. They can be used to connect parts with each other by bolts, studs, pins and rivets. If the hole is thrilled in order to cut the thread, it is worth paying special attention Select the diameter of the drill. Due to its beating in the cartridge, a breakdown of the hole, which should be taken into account. Approximate data are presented in the table.

To reduce the breakdown, the drilling is performed in two stages: first the drill of a smaller diameter, and then the main one. The same method of serial drill is used when it is necessary to make a hole of a large diameter.

How to properly drill metal drill

The peculiarity of the drilling of metal drill is that it is necessary to manually hold the tool to give it the correct position, as well as ensure the required cutting speed.

After marking the workpiece, the center of the future hole should be labeled. This will prevent the drill offset from specified point. For convenience, the workpiece should be clamped in the locksmith vice or put on the stand so that it takes the stable position. The drill is installed strictly perpendicular to the surface that you need to drill. It is important to avoid his breakdown.

When drilling a metal on a drill, you do not need to provide great Pressure. On the contrary, it should decrease as progress. This will prevent the breakdown of the drill, as well as reduce the formation of burrs on the output edge of the through hole. Make sure to remove chips. If the cutting tool has occurred, it is released, betraying the opposite rotation.

Selection of cutting mode

When a tool from high-speed steel is used, you can focus on the frequency of rotation according to the table. When working with carbide drills, permissible values \u200b\u200bof 1.5 ... 2 times higher.

Drilling metal products need to be cooled. If it is not used, the likelihood of loss to the instrument of cutting properties due to overheating. The cleanliness of the surface of the opening will be quite low. Emulsion is usually used as a coolant for solid steels. At home machine oil is suitable. Cast iron and non-ferrous metals can be drilled without coolant.

Features of the drilling of deep holes

The holes are considered deep if their size is greater than five diameters of the drill. The peculiarity of the work here is in the difficulties associated with the cooling and removal of chips. The length of the cutting part of the tool must be greater than the depth of the hole. Otherwise, the body of the part will block the screw grooves, according to which the chips are removed, and the fluid for cooling and lubrication is reached.

First, the opening is drilled by a rigid short drill on a small depth. This operation is necessary to specify the direction and centering of the main tool. After that make a hole of the required length. As you move, you need to extract a metal chips from time to time. For this purpose, coolant, hooks, magnets, or turn the part for this purpose.

Drilling through holes in metal blanks is made various tools With the use of special techniques. Many specialists in the performance of engineering works have to drill holes in metal structures often. These items have high elasticity, which forces the use of special cutting fixtures when drilling.

Types of drills and appliances for drilling for metal

Required devices for drilling metal products - electric and hand drills, as well as drilling machines. Working part of such devices - drillings of various forms:

• spiral;
• screw;
• coronalidal;
• conical;
• flat;
• cannon;
• rifle;
• centering;
• step.

Each drill has an individual marking, where the cross section diameter and the type of alloy is indicated on the tip from which it is manufactured. To drill the opening of the required diameter, the drill is necessary for several tenth millimeters already.

The drills are classified and in length:

• short;
• elongated;
• long.

To drill some materials, it may be necessary to drill a special sharpening with a diamond tip. With products from thin-leaf alloys, spiral drills may not cope. In some cases, for drilling deep holes, the product has to be recorded in vice, stops, conductor, corners with fasteners. This is done in order to safety and get high-quality openings.

Drilling modes of holes in metal products

For drilling through holes in metal products It is extremely important to pre-prepare for the process. In the instrument, you must correctly fix and send the drill. You need to adjust the frequency of rotations and other parameters. For too durable products it is recommended low speed Drill rotation. Indicator right drilling There should be a uniform long chips.

Types of holes and methods of their drilling

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

1. Through. Pursed metal blanks completely. It is important to ensure the protection of the surface of the machine from the random yield of the drill outside the product to avoid damage to the drill and the occurrence of sowing on the blank. Ideal for such types of work workbenches with holes where it is possible to put a wooden gasket under the blank. Holes in thin dwarfs are drilled by flat drills, because the spiral drill is capable of noticeably destroying the edges of the product.
2. Deaf. Performed on the necessary depth, not permeating the product through. In this case, an important point is to measure the depth, which is convenient to do, having limited the length of the drill focus on the sleeve or the cartridge of the drill with the fixing focus. Professional machines are equipped automatic systems Feed to the specified permissions, which allows you to fix the depth of the drill clock.
3. Deep. To this type of holes include those drills in which the length is five times higher than the diameter. When drilling deep holes, it is necessary to periodically eliminate the resulting chips using additional lubricants. It is often necessary to provide measures to ensure the cooling of the drill and the product itself, the temperature of which is rapidly rising until too high rates As a result of friction. This concerns billets from high-strength alloys. For deep holes use spiral drills.
4. Wide diameter. Drills of large diameter holes in products of large proportions is a very responsible and time-consuming process. For such holes, cone, coronal or stepped drills are used. Experts carry out abillation on low turnover of the instrument, trying to ensure the safety of the edges of the workpiece.
5. Complex shape. Sometimes it is necessary to carry out the drilling of through or deaf holes in the blanks of different density under the inner thread. The technology has to be divided into two actions: preliminary training Places and drilling itself.
6. Half. Half blanks are drilled by filling the cavity of wood. The disclosure holes can be obtained by one of two techniques: multiple of the drill drill with a smaller diameter to the entire depth of the workpiece, followed by reserving the drills of a larger diameter) and a decrease in diameter (driving to the desired depth of the larger diameter, followed by a smaller drill replacement). As a result, the hole is clearly centered.

Safety when drilling holes in metal blanks

Bring out the drilling of holes in metal blanks with high caution, not allowing the rapid destruction of the drill. Compliance uncomplicated rules When drilling will ensure security and will give a guarantee of the release of a quality product at the end of work:

1. On the eve of drilling, it is necessary to carefully check the fixation of all mounting devices on the machine.
2. You can proceed to work in special clothes to eliminate the hitting of any elements for moving parts of the machine. Eyes from hitting metal chip Protect special glasses.
3. At the entrance of the tip of the drill to a metal workpiece, it should already rotate on small circulation to avoid blunting.
4. Leaving drill out drilled hole It should be gradually, reducing turnover, but without stopping completely.
5. When the tip of the drill is not plugged into the workpiece, you will have to check the strength of the metal. When conducting over the surface, a file can determine the degree of strength. If the roughness on the alloy does not remain, you need to select a drill with a diamond tip or from a more solid material, and drill on small circulation.
6. Little diameter drills that are hardly fixed in the cartridge, it is recommended to wrap on the tail brass wire to increase the diameter of the girth.
7. If the work is carried out with a polished workpiece, you can wear a felt washer on the base of the drill to avoid damage when contacting the drill patron.
8. Fissure or leather gaskets are used for fixing metal blanks from polished or chrome steel.
9. When the deep holes are dried, a small fragment of the compressed foam placed on the drill will ensure a mix of metal chips. Also, the foam will give the ability to plunge the drill to the required mark in the production of deaf holes.

The power of electrical drills should be taken into account when drilling holes in metal blanks of various hardness. Electrical tool manufacturers label instruments, indicating the specifications on their housing. For drills of different power, the drills of the corresponding diameter are assumed.

Any, including drilling, you can trust the specialists from the company Proflselzermet. We ourselves define the desired hole diameter and pick up a suitable tool that we have big choice. In the end you will get perfect solution in short time.