The peculiarity of this steel is its increased viscosity. Therefore, a conventional tool overheats almost immediately, and it is impossible to work without effective cooling. And its organization in some cases is a rather complicated process. For example, if drilling is carried out in a horizontal plane, that is, vertically oriented samples. What should I do? One of optimal options– work with a cobalt drill. We will look at the features of such a tool and its types.

Cobalt drills are used not only when working with stainless steel. They are quite versatile, and their use is advisable in many cases: when drilling metals and high-strength alloys; differing in viscosity; and also when the requirements for the accuracy of the operation are specifically specified.

Tool Features

• Material – high-speed steel only.
• Coating the cutting parts of the drill with the Cº element (27th position in the periodic table) allows in most cases to work without artificial cooling.
• The standard angle (at the apex) is 135º.

Cobalt drills - general characteristics

• Even perfect drilling possible without pre-countersinking smooth surfaces. When positioned vertically, the tool does not “go away” to the side. As they say, it is self-centering.
• The hole is obtained with absolutely accurate dimensions, without burrs and other defects, which is typical for drilling with conventional tools. The risk of “biting” the stainless steel in the working area is eliminated.
• Cobalt drills are characterized by increased wear resistance.
• The drilling speed almost doubles compared to traditional analogues.

Types of cobalt drills

Unilateral

Double sided

The advantage is that essentially 1 product is 2 drills. In case of breakage (or dulling) of the edges on one side, the tool is quickly reinstalled, and work continues without any delay in searching for a new sample.

Cost of cobalt drills

Approximate data (in rubles/pcs) for the Moscow region. For cobalt drills with a cylindrical shank. Dimensions – in mm.

The range of this instrument is quite impressive, and it is impossible to list it completely. The price depends primarily on design features cobalt drill (single or double sided), diameter and length (total and working). A few examples for single-sided samples will help the reader get some idea of ​​pricing.

R6M5K5

• (0,5 – 0,9) – 27.
• (1 – 2) – 29.
• (2,1 – 3) – 30.
• 4 – 45.
• 5 – 54.
• (6 – 6,5) – 69.
• 9,0 – 193.

H.S.S.

From 25 rubles (1.0).

Considered one of the most reliable cobalt drills, which were produced back in the USSR. They were marked R6M5K5 and fully complied with the requirements of GOST No. 10902 of 1977. Nowadays it is quite difficult to find them on sale, since only a small number of enterprises are engaged in production. But it can be replaced with imported analogues (under the brands “Ruco”, “Bosch” or others). For example, HSSCo5 (according to the Western classification DIN 338R). The last symbols in the designation (K5 or Co5) indicate percentage element cobalt. This is what you need to pay attention to first.

Practitioners claim that tungsten drills are even more effective when working with stainless steel. But they have a significant disadvantage - fragility. Even a slight play in the chuck will negatively affect the usability of the drill - it will not last long. Considering its cost, you should think about whether it makes sense to purchase this product if you plan to work with a household tool (hammer, electric drill), which is also worn out.

Judging by the reviews on “metal” forums, there is another problem with tungsten drills. Sharpening them requires professional “eyes and hands.” Can everyone boast of this? So it turns out that for most of us such a tool is disposable.

When working with a cobalt drill on stainless steel, it is preferable to choose low speeds. This increases the accuracy of the operation and reduces wear.

A big mistake is made by those who, when drilling, practice the same technique as when using a conventional drill. Cobalt should not be regularly immersed in oil or water - it will quickly become unusable. This instrument does not require additional cooling.

Very few basics at the beginning.

Before work, you must select the cutting mode. What is it?
Elements of the cutting mode when drilling there are 3 main parameters:
Cutting speed when drilling, it is conventionally the peripheral speed (the speed of a point located on the surface) of the drill relative to the workpiece. ( In simple terms: "how fast the drill rotates", or the number of revolutions per minute depending on the diameter of the drill.) For example, the same cutting speed of 20 m/min is achieved if a drill with a diameter of 1.0 is rotated 6366 times per minute (rpm), and a drill with a diameter of 10.0 - 637 times per minute.
Innings - the amount of movement of the drill in the direction of the drilling axis per revolution in mm/rev (how quickly the drill immerses into the material).
Torque, perceived by the drill when cutting (what torsional load the drill experiences during operation).

These three parameters are mutually determining and their choice depends on:
-processed material;
- the material of the drill itself;
-equipment on which work is performed and type of cooling;
- other factors (surface roughness, contamination, etc.).

ABOUTfeatures of drilling stainless steels
The main feature (difficulty) when working with stainless steel is related to its ductility. As a result, a kind of sticking occurs on the working surface of the drill, which leads to overheating of the tool and its failure.
Therefore it is important:
- provide heat removal using cooling;
- use drills that are more resistant to heat and allow better chip removal.

Cobalt drills made from high speed steel HSSCo (M35) or similar designations (HSSCo5, HSSE, P6MK5), these drills are specially designed and recommended for drilling difficult-to-cut and stainless steels.
1. The composition of R6M5K5 includes 5% cobalt, which significantly increases the red-hardness of the drill - the ability to maintain high hardness and wear resistance obtained as a result of heat treatment when heated to red-hot temperatures.
2. The drill is made using more expensive grinding technology - i.e. the drill is not twisted into a spiral (like rolled drills), and the grooves are formed on grinding machine. As a result, there is no internal tension in the drill, and the surfaces are smooth, which significantly improves chip yield (important when drilling stainless steel).
3. The apex angle is 135 degrees with a cross-shaped point. This is the angle between the working edges of the drill (i.e., unlike conventional metal drills, cobalt drills look more “blunt”). This angle reduces the area working area drill, which reduces the load on it, and the cross-shaped point at the top reduces the dead zone (in this place the drill bears the greatest load) between the working edges.

How to drill regular stainless steel with a cobalt drill
If you can provide correct modes cutting, those. if you have a machine on which you can definitely set speed, flow and provide cooling, then we simply choose for stainless steel:
Cutting speed V=10m/min is recommended by most manufacturers for working with stainless steels and is necessary for selecting speed.
Then the revolutions can be calculated using the formula:
n=3180/D
for a drill with a diameter of 1.0 – 3180 rpm,
for drill 5.0 already 636 rpm
Innings: 0.005-0.01d mm/n, where d is the diameter of the drill. This means that in one minute a drill with a diameter of 5 mm should drill a hole with a depth of about 3 mm, and a hole with a diameter of 10 mm is already 1.6 mm.
Cooling:It is recommended to use oleic acid as a coolant.

If you work with an ordinary drill in " field conditions»
For cooling you can take olive oil(it contains 81% oleic acid) or sunflower oil - up to 40%, and if it is absolutely impossible to use liquid, then you can use lard or fat - they contain up to 44% oleic acid.
Drill at minimum speed (100-200 rpm). If the drill does not allow you to set the speed, use the on/off method and drill by inertia.
Only the minimum feed (pressure on the drill), while trying to ensure a uniform feed.

Very useful to know
1. It is a grave mistake to cool the drill by dipping it in water or something else (i.e., drill “dry” and then dip it, etc.). By these actions you will instantly damage the drill. Rapid heating and cooling leads to unpredictable consequences, a kind of uncontrolled tempering or hardening.
2. Cobalt drills do not have to be yellow (bronze), cobalt is not a coating, it is part of the high-speed steel from which the drill is made. The coverage is either: additional protection from corrosion, either it improves gliding, or this is just an image move by the manufacturer.
3. The given recommendations are valid when working with ordinary stainless steel, they have additional features when drilling thin sheet stainless steel.

How and with what to drill through stainless steel? I think you have asked this question more than once. Of course, such a need does not arise often, but when the question of drilling stainless steel arises, most craftsmen are unprepared.

You cannot take stainless steel with ordinary drills, although this primarily depends on your skill and knowledge in this matter. So let's deal with the problem))

Stainless steel differs from ordinary metal in that it is very viscous and when drilling, the drill instantly heats up. That is why the key to successful drilling of stainless steel is drill cooling. To do this, you can either use a special coolant for drills, or unscrew it yourself.

There are a lot of options, for example, you can use oil, which you can easily buy at the pharmacy, as an option - castor oil (ordinary castor oil), if you follow the instructions, then you need to drill stainless steel with oleic acid. And of course, you can use regular machine oil.

When drilling a horizontal surface, take some kind of plug or rubber washer, pour oil into it and drill through it. If you need to drill vertically, for example, a stainless steel sheet is fixed vertically, then you can use paraffin, roll it into a ball and stick it on the drilling site. We drill through it.

When drilling a diameter larger than 6 mm, you need to use the “double” method - this means that first you drill with a small diameter drill, then use a drill of the required diameter. For example, if you need a hole with a diameter of 5 mm, then first use a 2-3 mm drill, then 6 mm.

Well, the main, most important tool is drills. Drills are different, however recent years their quality has noticeably deteriorated. If you decide to try to drill stainless steel with ordinary drills made of R6M5 steel, then you are unlikely to be able to make a hole. Although, if the stainless steel sheet is not thick and everything is in order with cooling, then the case may burn out.

For trouble-free drilling of stainless steel, high-strength drills are used. There are also plenty of options. From personal experience— I believe that the best drills for stainless steel are old ones with a quality mark, with the addition of cobalt. The marking of such drills is P6M5K5. They are very strong, after all, in the USSR the quality mark meant a lot.

Until now, in our store they ask for exactly Soviet drills; of course, you won’t find cobalt drills during the day, but you can find standard P6M5 drills of some diameters.

Also, good results were demonstrated by ancient Sovdepov drills made of the now rare P18 steel. Finding such drills, especially with a quality mark, is now simply unrealistic. However, it is still found in stocks. Such drills sell like hot cakes even at a high price.

What to do if you can’t find Soviet drills, but you need to drill stainless steel? There is a way out, but be prepared to spend more money. Special stainless steel drills from the Ruko company are sold in stores; they have proven themselves to be excellent, but they are quite expensive.

For example, a drill with a diameter of 3 mm costs about 100 rubles. Not weak, to be sure. A large diameters already cost several hundred rubles. The drills are cobalt, although the marking is already imported - HSS-Co DIN338 (Co - cobalt). Its composition is similar to R6M5K5 steel, that is, the percentage of cobalt in the steel is also 5.

Well, the “coolest” version of drills is carbide for metal. They differ from one-sided sharpening, the angle is sharper. True, finding such drills is even more problematic than Soviet cobalt ones.

As an option, if you have some emery at home, you can independently resharpen a regular carbide drill for drilling stainless steel. It's a simple matter if you know how to sharpen drills.

Expert advice

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To oil paint does not dry out during storage and so that a film does not form on it, place a circle of thick paper on the surface of the paint and “fill it thin layer drying oils

" Polyethylene film, covering a balcony or greenhouse, is protected from being torn off by the wind by a string stretched on both sides at intervals of 10-15 cm."

"To work with concrete mixture it was easier, clay is usually added to it, but clay reduces the strength of the mixture. Add a spoon to it washing powder based on a bucket of water. "

"To prevent the screw, the head of which is hidden behind the obstacle, from rotating along with the nut being tightened, you need to throw several turns of thread or thin wire over it and lightly tighten the ends. Due to friction, the screw is held well in place. The ends of the thread can be trimmed after tightening."

"You can cut out a birdhouse entrance without a brace. It is enough to split front side boards in the center and cut out half-holes of the required size with a chisel or hatchet, and then connect the halves again. "

Wooden screw plugs crumble and fall out of the wall. Take your time to cut out the new plug. Fill the hole in the wall tightly with nylon from an old stocking. Using a nail of a suitable diameter heated red hot, melt a hole for the screw. The fused nylon will turn into a strong cork.

" Carpenter's level It is not difficult to turn it into a theodolite, equipping it with an aiming device from a slot and a front sight. "

"In order for two strips of linoleum to lie end to end, it is convenient to use a self-adhesive decorative film, placing it under the base of the noleum."

"So that the nail goes in the right direction and does not bend when driven into deep hole or groove, you should place it inside the tube, securing it with crumpled paper or plasticine. "

Before drilling a hole in concrete wall, secure a piece of paper just below. Dust and concrete fragments will not fly around the room.

"To cut a pipe exactly at a right angle, we recommend doing this. Take an even strip of paper and screw it onto the pipe along the sawing line. The plane passing through the edge of the paper will be strictly perpendicular to the axis of the pipe."

"Roll over logs or wooden beams A simple device will help - a piece of a motorcycle or bicycle chain, equipped with a hook on one side and secured to a crowbar on the other side. "

"In order for one person to be able to work with a two-handed saw, we recommend using a simple technique: move the saw handle from the top to the bottom position."

You can cut a piece of slate of the required size with a saw, but it is better and easier to punch holes along the line of the intended cut with a nail at a frequency of 2-3 cm, and then break off the slate on the support.

" The best way glue the tile to the wall: take bitumen, melt it and drop just four drops on the corners of the tile. Stuck on dead. "

It is most convenient to cut shaped holes in the manufacture of shaped window frames with a hacksaw with a turned blade.

"Making stained glass is a long and difficult task. You can make a quick imitation of stained glass. To do this, take thin slats or rods of vines, glue them to a sheet of glass, and then paint the glass and cover it with varnish."

“If you don’t have a dowel at hand, you can make it from a piece of plastic tube. The body of a ballpoint pen can also be suitable for this. Having sawed off a piece of the required length, make a longitudinal cut, about halfway, and the dowel is ready.”

"It is known how difficult it is to hang a door when working alone. But just shorten the bottom pin by 2-3 mm and the work will become much easier."

"A very durable, non-shrinking and fairly waterproof putty is made from bustylate mixed with any powder - chalk, gypsum, cement!, sawdust, etc."

"If you need to screw into the end particle board screw, drill a hole slightly smaller than the diameter of the screw, fill the hole with Moment glue (not epoxy!), screw in the screw after a day. The plate does not delaminate. However, the resulting connection can be placed under load only after a day. "

"Attach portraits, photographs, paintings to wooden frames It is more convenient to work with glass not with nails, but with the help of push pins bent at right angles. The buttons are gently pressed with a screwdriver. Compared to nails, the risk of splitting thin frames is reduced to a minimum. "

" Screw the screw into hard rocks wood is not so easy. If you poke a hole for the screw with an awl, and rub the screw itself generously with soap, then after such an operation the work will go like clockwork. "

To save time, the edge of the wallpaper can be trimmed with a sharp knife without unrolling the roll. To do this, you must first align the end of the roll and draw the edge border on the outside with a simple pencil. Working with a knife, the roll must be gradually turned in the direction of rolling.

For carrying at home large sheets plywood, glass or thin iron, it is convenient to use a wire holder with three hooks at the bottom and a handle at the top.

IF you need to saw a round stick into the distance, this work is most conveniently done using a template. It is made of a metal tube with a groove in the middle. The diameter is chosen so that the template slides freely along the stick.

It will be better and easier to work with a hacksaw if in the middle part you increase the height of the teeth by 1/3.

If on the front of the machine bow saw attach a load weighing about a kilogram, then the work will become easier. The load must be made removable so that the saw can be used to perform other work.

"A wax-like coating can be obtained by painting the surface with diluted PVA glue. To obtain desired color, you need to dilute the glue with water tinted with watercolors. "

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" Avoid using clamps when gluing wooden frames A laundry cord will help. You should put four short loops on the corners of the frame and two long ones to tighten the frames diagonally. The angles are adjusted using sticks that twist the middle loops. "

"How to silence a creaking floorboard? Between the floorboards you need to drill a hole at an angle of 45° with a diameter of 6-8 mm, drive a wooden pin into it, lubricated with wood glue, cut off the protruding end with a chisel and putty on the floor surface."

"To make it easier to sand a floor covered with varnish or paint, iron it with an iron through a damp cloth - and the work will become easier."

"Slight rotting on wood can be eliminated as follows: the affected wood is removed from the healthy layer, and then soaked in a 10% formaldehyde solution. After drying, the area is puttied and painted over."

" Door hinges will not creak if they are lubricated in time - this is a long time ago well-known rule. But you can do without lubrication. To do this, you need to make a washer from a polyethylene cork and put it on the hinge pin. "

" Out of order door latch If the spring is broken, it can be repaired as follows: the role of the spring can be successfully performed by a piece of rubber tube with a diameter of 15 mm or a piece of elastic rubber installed between the bolt and the latch body. "

We offer a simple device for fixing the window frame in the open position: a wooden or plastic plate in which a number of holes are drilled for the latch. The plate is attached to the window frame with a screw.

"Cut to sheet material big hole can be done in a simple way: clamp a nail in a vice (it will serve as an axis) and a piece of a drill (this will serve as a cutter). The circle is cut by rotating the sheet around its axis. "

Special drills for stainless steel and cooling compounds for them allow you to quickly and comfortably make a hole of the required size in stainless steel.

1

Many home craftsmen, accustomed to doing everything at home with their own hands, are very surprised when they are unable to drill a hole in “stainless steel” using a regular drill. Such steel differs from other metals in its increased viscosity, so the drill almost immediately heats up as soon as a person begins to process a product made of a stainless alloy.

This means that the operation can be successful only if you take care of high-quality cooling of the drilling tool.

To cool the device used for drilling holes in stainless steel, a special lubricant composition, consisting of sulfur and machine oil. Sulfur can be used either colloidal or special for fumigation. IN construction stores the latter is sold under the name “for fumigation” (sometimes it can be called “sulfur color”). As a rule, it can be used without any additional preparations. If you purchased sulfur of large fractions, you should first thoroughly grind it and only then mix it with machine oil.

Drilling holes in stainless steel structures will be many times more effective when using a cooling composition made on the basis of fatty acids and the same sulfur. You don’t need to buy these acids anywhere; make them yourself. To do this, take the cheapest laundry soap, grind it, and then pour the resulting mixture into hot water. Hydrochloric acid is added to this composition and waited until the fatty acids we need begin to float to the surface.

As soon as the acids rise to the top, it is necessary to pour into the container where the operation is performed, cold water(no need to feel sorry for her, the more you pour, the better). As a result, the fatty acids will begin to solidify, and they can be removed from the surface of the liquid without the slightest difficulty. The sounded process of isolating the required compounds (soap into hot water - cooling - removing acids) can be repeated several times (3-5).

Mixing fatty compounds with colloidal or “fumigating” sulfur is carried out in a six to one ratio. That is, for one part of sulfur you need to add six parts of acids. Professionals assure that with such a cooling composition it will not be difficult to drill through “stainless steel” of any thickness (if, of course, you follow other recommendations, which we will discuss below).

2

In cases where holes are drilled in a horizontal plane, it is recommended to pour the prepared cooling liquid into a small rubber washer or plug and carry out the procedure through it. During processing vertical structures You can attach a paraffin ball to the drilling holes. This will greatly facilitate the process - you can easily drill a product that is in an awkward spatial position.

Another feature of drilling holes in stainless steel is that either electric drill that are used to carry out the procedure must be set to minimum speed. Their number can vary from 100 to 600 per minute. If you set a higher number of revolutions, even a high-quality lubricant will not be able to effectively cool the working tool.

When using a drill equipped with an electronic regulator, it is easy to set the required speed. More problems arise when there is no such regulator on the instrument. But even in such a situation, there is a way out: start the electric drill for a short time (literally for 1–2 seconds); Press "Start" immediately. In such a short time, its collector motor will not be able to gain high speed.

3

You have prepared the cooling lubricant, studied all the recommendations for correct drilling“stainless steel”, and now you can move on to the most important thing - selecting a special drill. Without it, you won’t be able to drill through stubborn metal. In Soviet times, cobalt shank drills were always used to work with stainless steel cylindrical R6M5K5. They were made according to State standard 10902–77. P18 drills with a cobalt content of five percent were also used.

Nowadays it is almost impossible to find such devices for drilling holes. But it doesn't matter, because construction market offers us a lot of their foreign analogues. Imported drilling tools are produced according to DIN 338 and are marked HSS-Co, from which it becomes clear that the drill material contains at least five percent cobalt (similar to P18 and P6M5K5). It is cobalt that gives the tool the required hardness and makes it relatively easy to drill stainless steel.

In addition, carbide metal drilling tools demonstrate a good effect in processing stainless alloys. Such drills are characterized acute angle sharpening (it is done on one side). But purchasing them is not easy; not all construction stores sell them. And the cost of such devices is objectively high.

Some tips on drilling stainless steel:

• If you are drilling thick steel (more than six millimeters), it is advisable to perform the process using a double method. Its essence is that you first need to make a small “hole” with a drill with a small diameter and only then use a tool with the required cross-section.
• Drilling of products with a thickness of 1–2 millimeters can be done at normal speeds (up to 100 per minute), but provided that cutting edge This tool is sharpened to approximately 120 degrees.
• Stainless steel less than one millimeter thick must be processed step drills, which provide ideal round holes without burrs at their ends.