In construction and finishing works, drilling of holes does not occupy a dominant, but quite noticeable role. And only at first glance it seems that drilling is simple - press the drill button and that's it. Each material requires the selection of a suitable drill, the right speed and pressure on the drill, the method of cooling the drill and the removal of chips - all this is literally felt intuitively with experience. And our tips will help beginners.
To begin with, let's define Will the existing drill be able to handle those holes that you want to drill. The determining parameter in this case is the power of the drill. An ordinary household drill with a power of 500-600 W copes with holes up to 10 mm in steel and up to 25 mm in wood. An impact drill of the same power can drill a hole up to 13 mm in concrete or brick. If your work requires more, then you need to choose a drill more powerful.
The choice of tool and drilling modes is highly dependent on the material to be drilled and the diameter of the hole.
1. How to drill wood, plywood, fiberboard?
Drilling small holes in soft materials is no problem even for beginners. You don’t need to press hard on the drill, the speed should be slightly above average - the hole will be cleaner. Too high speed can cause the drill to heat up due to friction, the wood will start to burn. This is a good way to start a fire, but the part will be damaged.
For holes up to 10 mm in diameter, conventional metal twist drills can be used. When drilling deep holes in wood, especially in resinous rocks, the drill is needed more often (every 10-15 mm drilled) remove and clean the spiral grooves from chips. This must be done carefully so as not to burn yourself on the hot end of the drill.
When drilling very small holes (up to 1.5-2 mm), any careless movement with a drill, the slightest misalignment leads to breakage of the drill. Drills smaller than 1 mm can generally be broken by the weight of the drill by setting the drill at the drilling point. In order not to translate such drills in batches, keep in mind that wood, fiberboard, plain plywood can be drilled with a piece of paper clip or a nail. The end of the "tool" is bitten off with side cutters at an angle - and a tolerable drill is obtained. The drilling point must be pricked with an awl.
Special twist drills for wood at first glance resemble drills for metal, but the cutting part is sharpened differently (with a point in the center and edges), and the flutes are wider. This results in cleaner holes and better chip evacuation. The diameter of such drills is from 3 to 50 mm.
Large diameter drills often have a hex shank, which prevents the drill from turning in the chuck. Hex shank extensions are also available for drilling conventional short deep hole drills.
The drilling speed is selected based on the diameter of the drill and the hardness of the wood. Holes up to 15 mm can be drilled at 1400-1600 rpm, 15-25 mm at 1000-1200 rpm, 25-50 mm at 500-600 rpm. For hardwoods, the speed should be reduced by 1.5-2 times.
For drilling holes in wood from 10 to 60 mm, drill bits are produced. Outwardly, they resemble a spatula with a point in the center.
Such large diameter drill bits much cheaper than spiral, this is their main advantage. Drilling deep holes with feather drills is not very convenient. The drill does not eject chips, it has to be pulled out and the hole cleaned by hand. Turnovers when drilling can be kept higher. For holes up to 25 mm - up to 2000 rpm, over 25 mm - 1500 rpm. For solid wood, the speed must be reduced by 1.5 times.
For drilling large and deep holes(for example, holes for wires and pipes in wooden load-bearing beams) use Lewis drills. Such a drill looks like a drill with a screw on the end.
Wide flute with a small angle of inclination effectively removes chips. Lewis drills are produced with a diameter of 10 to 50 mm. Holes up to 15 mm are drilled at 1500 rpm, 15-25 mm - at 1000 rpm, 25-50 mm - 500 rpm. For hardwoods, the speed is halved.
For special types of woodwork, Forstner drills, milling drills, hole saws and hole saws are also used.
2. How to drill chipboard and laminate
Drilling chipboard and laminate is generally no different from drilling wood. Some difficulty may arise due to the heterogeneity of the chipboard - because of this, it is difficult to start drilling exactly in the intended place. To avoid this first poke a hole with an awl and drilled with a drill with a diameter of 2-3 mm. Then drill with a drill of the desired diameter.
The laminate can be easily drilled with both conventional wood drills and crowns of any diameter. When drilling laminated chipboard for furniture, it is convenient to use a specialized tool. For example, holes for confirmations (special self-tapping screws for furniture assembly) are drilled with a special drill with three cutting parts. This allows you to simultaneously drill the attached part and make a pilot hole for the threaded part in the main part.
3. How to drill plastic and organic glass correctly
Plastic and organic glass (polycarbonate, plexiglass), unlike wood, have a uniform structure without fibers, but melt easily. At the same time, it is possible "Bogging" and breakage of the drill.
Holes of small diameters (up to 10 mm) can be drilled with conventional metal drills at low speeds (up to 500 rpm). The place of drilling is desirable to be "pierced" with a hot nail. The drill needs to be brought out and cooled in water quite often.
Holes of a larger diameter or complex shape are easiest to drill along the contour with a 2-3 mm drill, saw through the jumpers with a jigsaw or hacksaw blade and file the edges with a file.
4. How to drill brick and concrete?
Concrete and brick cannot be drilled with a conventional metal drill. Or it will work, but for a very short time. The material in this case will play the role of a grindstone and simply dull the drill. Holes in brick and concrete are drilled (or rather, drilled) using impact drill or hammer drill. These tools not only rotate the drill, but also strike it.
In impact drills, the impact is mechanical. The details of this mechanism wear out quickly, so drilling with impact for an impact drill is an auxiliary mode and it is better not to abuse it. In perforators, the blow is carried out by an electromagnetic or electro-pneumatic mechanism; it can work hundreds of times longer. And the impact energy of the perforator is much higher, with a good drill, concrete is drilled with a perforator no worse than solid wood.
Before drilling a wall, be sure to check if there are plumbing, heating or electrical wires in it. With pipes, everything is usually clear, but it is better to check the presence of electrical wiring with a special device or, in extreme cases, with the simplest home-made hidden leash finder.
Used for drilling brick and concrete carbide tipped drills. Traditionally, they are often referred to as "winning" drills, although other materials are increasingly being used to make tips, for example. Wolfram carbide.
Please note that drills for drills and punchers have different shanks. And if a drill (drill) for a puncher with an SDS-plus shank can still be somehow clamped into a drill chuck, then a drill with a simple cylindrical shank will not twist.
At drilling brick or concrete with an impact drill choose medium speed. At high speeds, the drill will overheat and fail, at low speeds, drilling will be inefficient. You need to press the drill very hard, because the impact energy depends on the pressing force, and periodically remove the drill to cool.
When drilling with a hammer drill, the revolutions are quite low (800-1000 rpm) and there is no point in pressing hard on the tool- impact energy is determined only by the perforator mechanism. It is enough that the drill does not bounce off the concrete during impacts (5-6 kg).
Holes for dowels are made 10 mm deeper than the length of the dowel. This will get rid of problems if a little concrete or brick dust remains in the hole.
5. How to drill glass, porcelain, ceramic tiles?
Glass and porcelain are very hard and brittle. An ordinary drill simply does not take these materials - it slides over the surface, and when drilling with a blow, the product breaks. Therefore, the drilling of glass and porcelain is actually done by grinding with a special glass drill. Glass in this case simply turns into fine glass dust.
It looks like a small sharpened spatula. The spatula is made of hard metal and may have one or two cutting edges.
There are also drills with two mutually perpendicular spatulas, resembling a Phillips screwdriver. This drill has four cutting edges. Drills with a large number of cutting edges are more expensive, but they also drill faster. The diameter of the spatula drills for glass is from 3 to 12 mm. Holes of a larger diameter (100 mm) are drilled with diamond tubular or sliding drills.
Drilling glass and porcelain is carried out at low speed - up to 300 rpm, without a hit, clockwise only. Be sure to use a coolant. The best results are obtained by applying rosin solution in turpentine(1:2-1:3) or camphor in turpentine(3:4). You can also use silicate paper glue. In extreme cases, you can use pure turpentine and even water. To prevent the liquid from spreading, a plasticine rim is made around the drilling site. As it becomes contaminated with glass dust (turbidity), the liquid is replaced with fresh one.
To avoid chips at the exit, the glass is drilled from both sides. First, on one side - by 0.7-0.8 thickness, then on the other. In order to drill a hole exactly in the designated place, you can mark the center of the hole with a diamond glass cutter.
Ceramic tiles are drilled with a drill on glass. The most difficult thing is to start drilling exactly in the right place. Here, too, you can use a diamond glass cutter and mark a point on the glaze. Experienced craftsmen set the drill to the drilling point and press it hard. This is enough to destroy a small area of glaze to fix the drill. When drilling tiles already attached to the wall, it is important to stop in time and not start drilling the wall material itself. This can ruin the drill very quickly. Therefore, after passing through the tile, the drill is changed and drilling is continued with a more suitable tool for the wall.
The hard layer of glaze on a ceramic tile is thin enough to allow drill small holes with carbide-tipped drills designed for brick and concrete. To do this, you need to use a new, well-sharpened drill. And here, too, the most important thing is to start drilling in the right place. The drill tends to slip to the side.
If you are not sure about the hardness of your hands, then you can go for a little trick - stick a piece of adhesive tape in the right place. If there are a lot of holes, then it is better to make a jig. To do this, a hole for the drill rod is drilled in a wooden block 40-50 mm thick. On one side, the hole is drilled so that the carbide plate at the end of the drill fits into it. From below, several pieces of thin rubber can be glued to the bar - this will prevent slipping.
In this case, you can not do without an assistant. First, the drill is set at the drilling point, the block is lowered, and the assistant holds it firmly in place. After that, drilling begins - slipping is excluded.
Metal drilling
When drilling a hole in metal with a hand drill, the drill tends to jam. A wooden cork, previously hammered into the hole, will help to correct this defect.
It is not difficult to drill a hole in a thin metal sheet if it is clamped in a vise along with a block of wood. It is most inconvenient to drill thin metal sheets. They continually strive to escape and injure the driller.
Cut yourself out of steel "shovel" with a comfortable handle. Fasten the workpiece with clamps to the upper surface of the "shovel".
Those who have tried it know that a large diameter drill will "break" the hole, and it will be uneven. Place a piece of rubber or a rag folded in several layers under the drill and start working. The hole will be straight.
To cut blind holes in a part, you can use a piece of a round file clamped in an electric drill chuck. In order not to damage the back wall of the part, the working end of the file fragment should be slightly rounded on the emery wheel.
It is very difficult to drill a radial hole in a metal bar or tube. Especially if you're trying to do it with a hand drill. This task can be facilitated in this way: drill a hole of the appropriate diameter in a wooden block, insert a tube there and calmly drill, without fear that the drill will slip off.
If a blind (non-through) hole in a metal Part is filled with paraffin, then the thread cut on it will be clean.
wood drilling
Drilling a large hole in a board at home is a very difficult task, because the shank of a large drill cannot be clamped in the chuck of a hand drill. A hole with a diameter of 15 to 40 mm can be made using a simple device consisting of a metal rod and a hacksaw blade of the right size. Its cutting edges are sharpened at an angle of 45 degrees, inserted into a longitudinal slot previously made in the rod, and soldered or fixed with a wedge that is driven into the slot.
A person tempted by experience will never start drilling a round log before fixing it securely. He knows that, without taking precautions, he most likely will not be able to drill a hole exactly along the intended path, and besides, he may lose his drill.
Place a spring 1.5-2 cm long between the handle and the “runner” at the hand drill for wood, and even with sudden movements of the “runner”, the finger that accidentally finds itself between it and the handle will not be pinched.
When drilling a large diameter hole (20-30 mm) in a tree, the necessary drill or perk may not be available. In this case, drill a hole of a smaller diameter first, and then insert a flat steel washer (preferably new) into the brace chuck and go through the hole again. This method is also applicable for countersinking holes.
If you need to drill many holes at right angles in wooden parts, then take a hardwood cube, drill a reference hole in it with great accuracy. And then use this conductor in your work. A cube put on the drill will simultaneously serve as a drilling depth limiter.
A cork capsule from lemonade or beer is quite a good substitute for a drill when it is necessary to drill a compass needle in a wood holder, then reduce the risk of breaking it when a hole with a diameter of about 20 mm is made in a fibrous material or plaster. Pierce the plug, put it on the bolt, secure with two lock nuts, and drill.
It is difficult to make a hole in plywood, it splits. Take a steel tube of the desired diameter, sharpen the cutting edge inside with a round file and cut out teeth on it with a triangular file. Insert a wooden cylinder with a nail without a hat inside the tube. When working, the end of the nail, protruding by 1-2 mm, is the guide.
So that when drilling small parts from sheet material, they do not scroll, we recommend placing sandpaper under them.
If you fix a drill with a diameter of 0.8-1.1 mm, you will drill holes of small diameter in wood, textolite, and plastic.
There are quite a few devices for cutting large diameter holes in sheet material - plastic, plywood, chipboard, etc. You can use the design: a bracket is bent from a strip of steel 2-3 mm thick, its ends are sewn in, and a hole is drilled in the center, then the bracket is put on a bolt with a pre-sawn head. For work, the device is clamped in the chuck of an electric drill.
You can cut a large hole in a sheet material in a simple way: clamp a nail in a vise (it will serve as an axis) and a drill bit (this will be a cutter). The circle is cut by rotating the sheet around the axis.
A circle of any diameter can be cut out of plywood accurately, neatly and quickly using a wooden plank and two pointed nails driven into the plank.
A pencil sharpener bit (sold separately) can be used successfully for boring holes in wood and plastic. It is fixed in the chuck of an electric drill and the edges of the hole are processed.
A potato peeler in the hands of a craftsman is an almost ready-made tool for processing rounded holes in plywood. You only need to sharpen its cutting edge.
When drilling a board or plywood, remove the burrs at the same time, for which you put several thick felt rings on the drill.
Drilling in concrete
It is easier and faster to drill concrete with an asymmetrically ground carbide drill. However, we advise you to mark and start the holes with a drill with a conventional sharpening.
When drilling a hole in the ceiling, crumbs of concrete and plaster scatter in all directions, get into the eyes, behind the collar. Make a funnel out of spring wire, cover it with plastic wrap and put it on the drill.
If you drill into a concrete or brick wall made in a shoe polish tin, the dust will collect in it instead of flying into the room.
If you didn’t have a Pobedite drill for drilling concrete, you can replace it with a punch from the New Settler’s Dream set. Inserted into a drill chuck, it takes concrete well.
When drilling a hole in concrete or brick, the drill bit will last longer if it is periodically moistened with water. It is convenient to use an elastic plastic bottle as a water reservoir.
When drilling holes in the wall, it is very difficult to keep the drill in a strictly horizontal position. Attach to her
a small level or a vial replacing it with electrical tape, and the matter will be greatly simplified.
If it is necessary to drill a through hole in the wall, but the length of the drill is not enough, what should I do? Try to perform this operation in two stages: on one side and on the other side of the wall. Having drilled a hole at the intended point, place the magnet in it. Then use the compass to find the drilling point on the opposite side of the wall. The compass needle won't go wrong.
Drilling is one of the most frequently performed operations by a home master. And any master faced problems when drilling, especially if the work is thin. And fine work is most often found: the drill took half a millimeter - the furniture door is skewed or a simple towel hook in the bathroom stood obliquely, and it is impossible to re-drill: the tile has just been laid. Elegance and "oakness" are incompatible, so you need to know how to drill with a drill correctly.
Safety
In terms of electrical safety, a commercially available power tool belongs to class II: double working insulation, it is permissible to use it without additional grounding, i.e. such a drill can be plugged into a regular, non-euro socket through an adapter. At the "iron bazaars" you can find a class I tool ("industrial"), with a ground terminal on a metal case. It is dangerous to use it in everyday life, and its cartridge is most often used for a drill with a tapered shank (Morse taper), unsuitable for rotary percussion drilling. Therefore, do not take such a drill, even if it is powerful and inexpensive.
Class I is indicated on the nameplate of the drill, and if there is no designation, the case is partially or completely plastic, and the cord with the euro plug is a class II tool. Class III - a power tool for an operating voltage of up to 42 V (low voltage) can be recognized by the class designation on the nameplate and by a special plug with flat cross-shaped contacts. For the home, it is suitable, but inconvenient: you need a powerful step-down transformer.
For protection against ingress of foreign objects and moisture, power tools and equipment are marked with the letters IP (Ingress Protection) with two numbers after them: the first - from foreign objects, the second - from moisture. If the protection for any position is zero, the letter X is put instead of the corresponding number. So, IP32 drill - can be used outdoors in good weather; IPX2 - only inside, IP34 - outside in fog and drizzle, and IP68 can work during Samoom in the Sahara and under water.
Important: the first number 2 means that the device is finger-proof; for example, a household socket has a degree of protection IP22. But this in no way means that if a drill chuck with the same degree of protection is grabbed by hand during operation, then it will stop by itself. The IP standard does not guarantee foolproofing.
Cartridge
A conventional three-jaw chuck is accurate and good at rotary drilling. With a rotary percussion drill, it quickly loosens up in it, and the cartridge itself loses accuracy and can completely fail: the threaded clip of the cam mechanism bursts. For work on hard brittle materials, a three-jaw chuck is suitable for occasional use or with a diamond working body in rotation only mode.
In a keyless chuck (it can be recognized by a corrugated plastic holder), the drill is clamped by a collet. Such a cartridge holds the drill better during rotary impact drilling, but is less accurate and is not suitable for fine work. Powerful drills are supplied with a two-sleeve collet chuck - clamping and loosening are done by different rings.
The SDS cartridge (Steck-Dreh-Sitzt, German “inserted-turned-sits” or Special Direct System, a special direct system, English) was invented by Bosh. SDS is ideal for construction work: the system of curly grooves, see Fig., absolutely securely fixes the working body according to the principle of a Chinese puzzle; changing the drill is done with just two easy movements.
Unfortunately, SDS is not suitable for metalwork and carpentry: the accuracy of centering the drill is insufficient. The adapter from a three-jaw chuck to SDS does not make sense: it will become loose from vibration, like a conventional drill. Therefore, the SDS drill is incompatible with the usual fit of the working body.
Note: There are three types of SDS fit: SDS+, SDS Top and SDS Max. SDS Top is rarely used, as an intermediate and generally unsuccessful option; SDS+ is designed for one-handed tools up to 5 kg; SDS Max - for heavy two-handed.
Power and RPM
When buying a rotary impact drill for general work, you do not need to save on power. The power reserve is needed to create the necessary torque at low speeds. The external characteristic of a collector electric motor with sequential excitation used in drills is close to ideal, but a low-power motor overheats at low speeds from high current. It is also advisable to purchase, if not included, a front captive handle.
The maximum speed of the drill is also important. The diamond tool is literally "eaten up" before our eyes at a rotational speed of less than 1600-1700 rpm; its normal operating speed is from 2500 rpm. Carbide tools need at least 1500 rpm. If you meet a drill at 600-1200 rpm, this is a special tool that is unsuitable for general-purpose work.
For precision work on metal, a simple, only with rotation, low power drill - 120-200 watts is best suited. It will be very useful to have a bed that turns the drill into a desktop drilling machine. And if you also fork out for a turntable to the bed, then a dental bur can mill small parts.
Network or battery?
A cordless drill is needed for a home master in two cases:
- If you work on the side - your more or less regular earnings.
- If you have a non-electrified cottage or garage.
In any case, an expensive professional drill with a lithium battery and a charge time of 10-20 minutes is unlikely to pay for itself. This is an option for professionals working full-time day-to-day. And you can use a regular alkaline battery, charged in 4-8 hours. In extreme cases, it can be “pumped up” on a hole or two in half an hour.
Section Summary
All of the above can be summarized in the following recommendations:
- Regular construction work, including metal structures - need a hammer drill and impact drill 350 W or higher.
- Periodic homework - rotary impact drill from 250 watts.
- For precise drilling - an additional precision drill for rotary drilling at 120-150 W; preferably - with a bed.
Drill
Drills for drills are most commonly used of the following types:
- Spiral - come in tool steel, coated with hard alloy, with a hard alloy insert and solid carbide. Used for all types of work on any materials.
- Fountain drills can drill wood, MDF and plastic. Allows you to drill large holes. They are made either in one piece or as a set of a shank with a groove and several inserts of different diameters. Such a set is cheaper than a set of solid nibs, but less accurate.
- Crown (crowns) are used for excavating holes in hard brittle materials - stone, concrete and drilling wide holes in chipboard and fiberboard. Available with and without centering twist drill. The latter are cheaper, but only suitable for stone and require strong working skills.
- A circular drill (central drill, ballerina) drills holes of large diameter in thin, strong, but brittle materials with a decorative front surface, such as tiles or polished decorative stone. The drilling diameter of the circular drill can be continuously changed. Rotary impact drilling with a circular drill is unacceptable.
- Diamond drills are thin-walled tubes made of a special alloy with diamond coating. They can drill glass, polished decorative stone, glazed ceramic tiles. Roads require careful handling and precise adherence to drilling technology.
Drill sharpening 
Drill sharpening
Self-sharpening of drills is acceptable for twist drills and feather drills. The first ones are sharpened with a diamond file - they are made of tool steel. Cheap kits can be made from regular carbon steel; their feathers can be edited with an ordinary needle file.
Twist drills are sharpened with an emery wheel (carbide - diamond) using a wedge tool with an angle equal to 180 degrees minus half the sharpening angle. So, with a sharpening angle of 120 degrees, the wedge angle is needed at 30 degrees. In the hypotenuse (oblique side) of the wedge, a longitudinal hollow or a blind hole is made, in which the drill is smoothly rotated during sharpening. The best sharpening is obtained with a fine ("velvet") hand emery wheel, see fig. below.
Different materials require different sharpening angles of the drill. Metal is most often drilled with drills with a sharpening angle of 116 degrees, concrete and stone - 90 degrees, wood - 60-90 degrees. The exact angles and sharpening methods for different types of drill bits for different materials can be found in material handling reference guides.
About Carbide
Hard alloys for drills are made on the basis of compounds of boron, tungsten or zirconium. The cheapest ones are based on boron, but such a drill will take concrete with great difficulty and will quickly wear out. Such drills are marked "by stone". It is impossible to drill decorative materials with them - the edges of the hole will chip off. Tungsten and zirconium compounds differ primarily in durability: zirconium compounds last longer. They are correspondingly more expensive.
What and how to drill
For any drilling, the locations of the holes must be marked. For metal, this is done with a punch, and for glass, ceramics and stone, either with a special diamond punch, or with a half of a victorious roller from an old glass cutter, sandwiched in a homemade clip. Punching (more precisely, scratching with rotation) hole marks in brittle hard materials must be done manually. Now let's move on to drilling technology.
Steel, brass, bronze, solid alloy
Drilling of metal of normal viscosity is carried out at medium drill speeds, 400-1000 rpm, depending on the hole diameter: 400 revolutions - with a maximum drill diameter of 13 mm for a conventional drill; 1000 - with a diameter of 3 mm. For smaller diameters, the speed is again reduced to the same 400 rpm for 1 mm.
Turnovers mean the maximum, at idle. In the process of drilling, the regulator itself will reduce them according to the tool feed, i.e. according to how hard you lean on it. The selection of feed for manual drilling on weight requires a certain skill: if the feed is too low, the crumb will go, the hole will turn out with uneven walls. And from the same crumbs, the drill will overheat and quickly become dull.
With excessive feed, the so-called drain chips will go - thick, curling in a spiral. The result is the same. In order for the feeding skill to be developed faster, even small holes need to be drilled with two hands, with a cap handle. The chips should be thin and brittle. For steels 42 and 44 (ordinary structural steels), chips with a bluish tint are acceptable.
Bronze and some varieties of duralumin require special attention: they do not give drain chips at all, and duralumin sharply loses strength when heated above 160 degrees. It is permissible to follow bronze by tint: its appearance is undesirable. Dural, on the other hand, must be cooled with liquid engine oil: if it boils, you need to press lighter.
You can set the idle speed by clicking the knob. If the drill is at 2800 rpm and the adjuster is 14 clicks edge to edge, then 1 click is 200 rpm. The adjusting characteristic of the regulator is not always linear, so you need to carefully monitor the drilling process and then give the necessary correction: know at what clicks of this particular tool you need to drill this material.
Note: when drilling steel and brass, lubrication is not needed, it will only prevent the correct chips from forming.
Sheet metal
For the same materials, but sheet, so that drilling does not lead to sheet deflection, two methods can be recommended:
- When drilling from the bed, give more speed, up to 1500-2000, and quickly “pierce” the sheet, which should lie on a wooden pillow. To prevent the sheet from turning and injuring you, it must be fixed with nails driven into the pillow at its edges, or pressed to the table with a clamp; better - two.
- When drilling on the fly, as soon as an increased resistance to the feed is felt (this means that the drill is about to come out), you need to drill the hole on the other side, flushing the “pimples” with a punch inside.
But a radical way to get a wide hole in a thin sheet of metal with an ordinary drill is to first drill a hole with a diameter equal to the thickness of the sheet, then expand it in one or three steps to the diameter of the required hole minus twice the thickness of the metal, and drill it clean. Each subsequent hole should be wider than the previous one by twice the thickness of the metal. The maximum allowable diameter is 5-6 metal thicknesses. That is, in a 2 mm sheet, you can drill a hole with a diameter of 13 mm, and it will be round, and not like a triangle with very smooth corners.
Aluminum is a soft metal, very ductile and fusible: its melting point is only 660 degrees. Because of this, when drilling, it can melt on the cutting edge, blur the hole, swell its edges and bite the drill. Therefore, when drilling aluminum, it is necessary to give one and a half times less revolutions than for other metals, cool the drill with liquid engine oil, emulsion or water, and feed the tool a little, without leaning.
The drill for aluminum must be sharp, factory-ground or sharpened on a special machine. Drills resharpened by hand are not suitable for aluminum.
Stainless steel
Stainless steel is drilled in the same way as structural steel, but with a solid carbide drill ground to metal. Such drills are very fragile, so you need to feed the tool easily and without the slightest distortion. It is best to drill with a low-power precision drill in the bed.
Wood, MDF and plastic
Commercial wood is drilled with a twist drill sharpened under a tree or a feather drill. Dense breeds (oak, beech, walnut) can be drilled with a hole saw with a center drill. Drill revolutions - 400-600 for a twist drill and 200-500 for nibs and crowns.
Drilling of plastic windows, MDF, plastic tiles and polished wood is carried out either with a special drill bit for wood (with shaped sharpening and a centering threaded cone), or with solid feather drills. In the latter case, a centering hole of 3-5 mm is pre-drilled; it can be drilled with a conventional drill. Turnovers are the same as for commercial wood; feed - easy, without pressure.
Concrete and reinforced concrete
Drilling of concrete is carried out with special drills for concrete with a superhard solder or insert, in a percussion-rotary way at medium or 2/3 of the maximum speed of the drill. The best option is the SDS drill. If reinforced concrete is drilled, then the drill hitting the reinforcement most often leads to its damage: the hard tip is chipped off. Therefore, before drilling reinforced concrete, it is highly desirable to determine the location of the reinforcement with a reinforcement detector; This device works on the principle of a metal detector.
Drilling holes in the walls for socket boxes is done with a crown on stone (for brick walls) or concrete, with the same precautions in the case of reinforced concrete. If the hole is drilled with a crown without a centering drill, then it is tightly, without skew, applied to the wall, pressed, and the drill is turned on sharply, with quick pressure.
There is a special tool and technology for through wall drilling, but this is the subject of a special description.
Ceramics and stone
How to drill tiles is, without exaggeration, a whole science. The material is decorative, chipping of the edges of the hole is unacceptable. Drill already laid tiles, so that cracking is also unacceptable. On a smooth surface, the drill can easily slip off, which again is unacceptable. Drilling - only rotation.
Drilling ceramic tiles is done as follows:
- A hole with a diameter greater than the thickness of the centering drill web is punched manually with a diamond or carbide center punch; its diameter is 2.5-3 mm. When drilling a hole with a large diameter, the diameter of the centering drill should be equal to the diameter of the centering rod of the circular drill.
- A centering hole is drilled with a concrete drill. When drilling holes for dowels up to 6 mm, you can immediately drill clean.
- With a finishing drill for concrete, the hole is drilled completely.
Porcelain stoneware is drilled in the same way as ceramic tiles. Drill speed - maximum, except for drilling with a circular drill; feed is light, minimal. It is desirable to provide continuous cooling of the working area with water. It is impossible to cool the tile with oil - when heated, it can spoil the decorative surface.
Drilling ceramics with a circular drill requires special care and firm hands: misalignment is not allowed, and the drill is not balanced. Even experienced workers need to drill with a drill with two hands, throwing the front handle on the drill. Turnovers - higher, but not more than 900, because. at large, an unbalanced drill will break the hole and cut off its edges.
Video: how to drill tiles
Solid stone and glass
Glass, granite and other brecciated (granular) hard stone with quartz inclusions should be drilled with a diamond drill. This is a job for an ace and a drilling virtuoso. A low-power precision drill is set to maximum speed, they are tried on, having aligned horizontally and vertically by eye, they are turned on immediately “to the fullest” and slowly, smoothly the drill is inserted into the material. Pressing and tilting are not allowed.
If the piece to be processed can be laid on the table, then glass and stone can be drilled from the bed in the ancient Egyptian way: with a copper tube with quartz (not sea shell) sand:
- A roller 1-1.5 cm high is made around the drilling site from plasticine or putty.
- Fine quartz sand is poured into the formed hole and moistened to a liquid slurry.
- A flat thin-walled copper tube is loaded into the drill chuck.
- The drill is set to the MINIMUM speed.
- They drill with a series of short light pecks at the weakest pressure. Sand eats into copper, and the points of its grains, which have the greatest strength, gnaw at the material.
Note: the exact diameter will not work, but you will get a dull spot around the hole.
Video: examples of glass drilling at home
Holes in pipes
If a piece of pipe can be laid in the center or clamped in a vise, then it is better to drill with an accurate drill from the bed. If you have to drill on weight, then after punching, the mark must be expanded to a diameter exceeding the thickness of the drill jumper. For metal, this can be done with a carbide drill, rotating it with your fingers with light pressure; on PVC - with the tip of a penknife.
Then the tip of the main drill is inserted into the hole with the drill turned off, the tool is leveled and tried on, as when drilling tiles, lightly pressed and the drill is turned on, gradually increasing the speed. If the hole diameter is more than 1/5 of the pipe diameter, then a centering hole with a diameter of 2-4 mm is drilled first. In general, with some skill, drilling holes in pipes is not a difficult job. You just need to be careful: when drilling on weight, the drill, splashing, can damage the wall or furniture.
square holes
Can you drill square holes? Yes, you can, if you use a drill in the form of the so-called Renault triangle - the simplest figure, as mathematicians say, of constant width. Renault drills come with a fixing frame; it is attached to the drill with a barbell and a clamp. The corners of the hole will be rounded, but the invisible area of the hole will be only 2%.
However, a drill can drill square holes only in wood, plywood and not very durable plastic: such drilling requires a lot of power, and there are huge lateral forces on the tool. Square holes in metal are drilled on special machines, but ceramics and stone cannot be drilled like this at all: lateral forces will blow the part into pieces.
Outcome
Somehow piercing a clumsy hole with a drill is a simple matter. But drilling an even, round and neat hole is a job for a real master, who is knowledgeable, intelligent and with skillful hands.
Each of us has repeatedly faced with the need to mount various objects on the walls that bring variety to the interior, create coziness, or simply remind of the pleasant moments of life. Most often, you have to mount lamps and sconces, paintings and photographs, mirrors and shelves on a concrete surface, install an air conditioner, or a TV. If in the case of a small painting or photograph you can get by with driving a nail into the wall, then when the question is about more massive and heavy objects, the question of drilling holes arises. In order to avoid misunderstandings when working with concrete, for example, breakage of the drill, blunting it, it is worthwhile to properly prepare the partition, choose a quality tool and choose the right drill.
Choosing a tool and working with it
When choosing a tool to drill a hole, you should understand that your work depends on it. A good drill accurately drills a concrete wall or other desired material, simplifies the drilling process, while a bad drill will require a lot of time, may not cope with the task, or complicate it. What you need to pay attention to when choosing a drill:
- Is it possible to change the drilling speed? - this point is important, because the correction of the speed mode will ensure accurate operation of the drill, helping it not to damage the surface.
- Is it possible to hammer drill and adjust the depth? – impact drilling can be applied to problem areas, softening them.
- Is it possible to hold the drill with both hands? - a drill is not an easy tool and therefore models that are equipped with handles should be preferred.
- Is the power of the tool sufficient for your work?
Having decided on a drill, before starting work, you need to get the hang of holding it. To do this, take the drill in one hand, like a pistol, place the other hand on the handle of the tool (if it is not intended by the design, the hand is placed near the cartridge). It is necessary to hold the drill in your hands strictly horizontally so that the hole does not turn out with distortions and at the wrong angle. Before turning on the drill, wait until it reaches ambient temperature. Sudden temperature changes can cause condensation to form. If you decide to take a break during work, unplug the tool from the mains.
Surface preparation
It must be remembered that the wall is looser than the following layers. Before you start drilling, you need to make sure that there are no wiring, pipes, electrical cables in the selected floor area. A metal detector will help to cope with this task, as it reacts to non-ferrous metals, iron and steel.
By ignoring this condition, you can stumble upon rebar, damage the drill, or cables / pipes that were hidden in the ceiling. If this section satisfies all of the above requirements, then a point is marked on the wall, and after that a small depression is made in it at a slow speed using a drill. It is also worth remembering that the surface of the concrete wall is looser than subsequent layers.
Drill selection
This point can rightfully be considered the main one, since the quality of work and the safety of the drill itself, as well as the accuracy of work, depend on a properly selected drill. Today, there are a huge variety of drills on the market: for working on wood, metal, concrete. The latter are distinguished by a triangular tip. For a concrete surface, it is best to use a carbide drill, for example, Pobedit. This type of drill grinds the material without tearing it, which is ideal for concrete floors.
If in the process of drilling the wall the drill does not go forward, colliding with a dense area, it is recommended to use a punch. After inserting the punch into the hole, it is beaten with a hammer until it begins to move forward and softens the problem area. After that, you can continue drilling.
It should be noted that without a punch, a perforator can easily cope with such difficulties, however, they make holes that exceed 13 mm in diameter. If you want to use universal drills when drilling, you need to remember that they require cooling, vibration is turned off and are only suitable for a conventional drill.
A little about the device of the drill and the installation of the drill
Drilling pattern for a concrete wall. A classic drill consists of a power cable, a button, a capacitor wire, a reverser, brushes and springs, an armature, a stator, a gearbox and a chuck, bearings, a key and fastening screws. A correctly inserted drill improves the quality of drilling, and is able to secure it.
The first thing to check when starting work with a drill is that there are no contaminants on the drill itself. A rag will be a great helper in cleaning drills. If the drill is loose, then there is a risk that it will fly out and injure the master. Accordingly, it is necessary to immerse the drill as much as possible in the cartridge (up to the stop!).
In no case do not try to "lengthen" the drill by partially immersing it in the chuck!
It is important to ensure that the drill in the tool is fixed strictly along the axis. In case of non-compliance with this rule, drilling in concrete will be performed poorly, the shape of the hole may be unpredictable, and the elementary effect of the beat of the drill will become the cause of all these misunderstandings.
The processing of metal parts belongs to the list of very complex operations. Drilling may be required when working in production, at home, in a garage, in a country house. For these purposes, drilling equipment, drills and accessories are used.
Metal products have increased strength and hardness, which leads to strict adherence to technology and the use of reliable and high-quality equipment. Drilling holes in metal is required to create a variety of collapsible as well as non-collapsible connections. For this plumbing procedure, you need a machine or a drill, a hammer with a plumbing center punch for precise marking of holes and a drill.
How to drill a hole in metal - technology
Processing of metal products is carried out in production, in the repair of a car, at home, or in the manufacture of various structures. Using the technology of drilling holes in metals involves the use of machine tools or hand drills. At the same time, the first option requires significant financial costs, since stationary equipment is not cheap.
The technological process of drilling consists in the gradual removal of a thin metal layer during the rotational-translational movement of the drill. Obtaining high-quality processing is impossible without reliable axial fixation of the cartridge and straight-line feed. For these purposes, special mechanical type clamps are used - conductors. These accessories are required when it is necessary to drill a hole in a piece of metal that is thicker than the diameter of the tool being used.
Before starting drilling, mark the center of the resulting hole with a center punch. To obtain high accuracy, it is necessary to select a drill 0.1-0.3 mm smaller than the required size of the treated area. A slight vibration of the equipment will break the drilled diameter to the required value. To reduce friction, coolant or a special lubricant is used. It can be engine oil or ordinary water.
When the edges of the drill are dull, they must be corrected, otherwise the tool itself and the workpiece can be spoiled. When working with hollow objects (boxes, pipes), a special wooden spacer is placed inside. If threading is required, drills are selected taking into account the breakdown of the drilling area. First, use a gimlet of a smaller diameter, after which they drill the main one.
How to drill metal with a drill
The main problem when working with a drill is its manual hold. In this case, it is necessary to strictly observe the direction, provide the necessary clamping force and control the drilling speed.
Having put the necessary marks on the product, the center of future drilling places needs to be punched, which will prevent the gimlet from moving. The workpiece can be fixed in clamps or placed on a special stand. When using a hand tool for holes in metals, it is necessary to monitor the strict perpendicular position of the drill.
Do not apply excessive pressure to the tool during operation. As you go through, the force decreases, which reduces the formation of burrs at the exit and prevents breakage of the drill. When biting the drill, it is released by reverse rotation.
If a large drilling depth is required (more than five drill diameters), special attention should be paid to cooling the cutting object and constantly removing metal chips. A short type drill is pre-used to obtain the required centering and feed direction. Chip removal is performed by turning the part over, with coolant, and also with hooks or magnets.
Drill Requirements
In order to drill a hole in metal with high quality, it is necessary to choose the right drill bits, taking into account the diameters, as well as the properties of the material. For this, high-speed tool steel is used. When drilling alloyed and carbon steel objects of a hardened type, cast iron, stainless steel and other hard-to-machine materials, carbide drills are used.
Before drilling a hole in solid metal, it must be pre-drilled with a smaller tool. Some cutting products contain cobalt additives that increase its wear resistance as well as durability. The letter "K" is added to the marking of this tool.
Power and speed at work
Its capabilities depend on the power of the equipment that performs metal drilling. Hand drills with a power of about 500-700 W are designed for drilling sections up to a maximum of 10-13 mm in diameter.
The rotation speed of the cutting tool when working on ordinary metal is low and medium (500-1000 rpm). The use of high speeds is fraught with rapid heating of the drill, which causes its annealing with softening. Drilling deep holes in metal should be done with moderate pressure and low speeds.
How to drill metal
For a full-fledged metal drilling process, the main parameter is the sharpness of the drill. The rate of blunting of the cutting edges directly depends on the hardness of the material being processed, the feed force, the rotation speed, the presence of cooling and other factors. The technology for drilling large holes in metal is that they initially drill with a small drill, and then use the main one.
For precise drilling, core drilling of the centers of future processed areas is mandatory. You can improve the process conditions by first dipping the tip of the tool in machine oil. In everyday life, ordinary soapy water is used. For the deep drilling process, it is necessary to constantly cool the working tool and remove accumulated metal chips in time.
Sheet
When working with sheet-type metal products, it is necessary to place a wooden block under the cut point, which will prevent the appearance of burrs. As a replacement for the bar, you can use any material that is less hard than the main one. At the final stage, it is recommended to reduce the feed force, which will also reduce the likelihood of dangerous burrs.
Holes in pipes
The main problem with drilling pipes is their precise positioning. In this case, the input drilled place often does not coincide with the output. Increasing the pipe diameter leads to even greater errors. It is almost impossible to maintain strict perpendicularity by eye, therefore, special purchased or home-made conductors and guides are used.
Stainless steel
Work with stainless steel is carried out at minimum speed, preferably with a cobalt drill. A value of 120-150 rpm will provide the required quality and cutting speed. In the absence of a speed controller, a short-term turn on of the drill is used, which will prevent the cartridge from accelerating to maximum values. You can use step drills, which greatly facilitate the process. For diameters over 15 mm, special "crowns" are used. Cooling of the working element is carried out with fat or olive oil.
Aluminum
The complexity of working with aluminum products lies in the material wrapping around the cutting edges. This greatly complicates the penetration of the borer into the depths and along the way expands the very place of processing. Accurate drilling requires more frequent removal of the drill from the part for cleaning and the use of coolant.
Safety
Any work, including metal work, must be carried out in compliance with all necessary safety measures. Workpieces of medium and large sizes are fixed on special fixtures or on the machine table. Small parts are held with a hand vise. Do not hold workpieces with your hands while drilling.
It is impossible to touch moving elements, throw belts on the machine pulley when it rotates. Chips are removed with special hooks or brushes. Sleeves on overalls are fastened or rolled up above the elbow, hair is hidden under a headdress, eyes are closed with safety goggles.
