Cut strained glass impossible in the usual sense. After hardening, the material changes its properties. Tempered glass is better known to the general consumer under the name "safety glass". Cutting it in the traditional sense will cause the material to simply collapse into many small fragments. However, despite existing limitations, great desire such material is quite successfully cut. The work boils down to the fact that the glass is first annealed, and after that it is cut. Then, if desired, the glass can be re-fired to make it very strong and safe again.

What you need to know about tempered glass before cutting it?

Tempered glass is characterized by increased strength. It is used for glazing balconies, loggias and skylights. A variety of furniture and translucent structures are created from this material. If you need to cut tempered glass, you need to carefully prepare for this process, carefully studying all the features of the event.

First of all, you should study the properties of tempered glass. At its core, it is a thermally polished material. For its manufacture, unpolished and polished glass sheets are used. Direct hardening is carried out in furnaces specially designed for this purpose.

Glass cutting should be done on a flat surface with a bed cloth or a sheet of paper.

In such a unit, the glass is heated to 680 degrees. At this temperature, partial softening of the material is noted. Next, the glass is rapidly cooled under the influence of uniform air flows. First, the surface layer cools down. In the process, the internal ones are subjected to residual compressive stress. It is thanks to him that as a result, tempered glass becomes so heat-resistant and mechanically strong.

According to average data, the strength of tempered glass is about 6 times higher than that of conventional material. Breaking it without the desire to do it intentionally is quite difficult. Even if a tempered glass product breaks, the material will turn into many small fragments without sharp edges, so it will not work to injure yourself on them in the way that could happen with ordinary glass.

All stages of work, including edge processing, are carried out in production. This is done even before the glass is sent to the furnace for tempering. After all related activities have been completed, the hardened material is not subject to any mechanical stress. If you want to change something, you will first have to anneal the glass.

The scope of such material is quite extensive. Tempered glass is popular in building and glazing door and window openings, shower cabins, furniture and other structures are made from it. So if you plan to make durable and reliable glazing, but do not have the skills to cut tempered glass, study the proposed instructions in detail and do everything in accordance with the manual. If you think that such a process is too complicated for you, it is better to immediately contact the services specialized company for ordering products of the desired shape and size, with all the required cutouts and holes.

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So can glass be cut after it has been tempered?

In fact, tempered glass can be cut. But you need to properly prepare for this so as not to turn a whole sheet into a mass of parts with blunt edges as a result. To destroy the sheet, it is enough to simply hit its end with any suitable object. To change the size of the product, create cutouts and other things, you need to adhere to the technology and, first of all, study directly the properties of tempered glass.

Example 1. Tempered glass cutting technology.

The manufacturing technology of tempered glass is such that in the process of its production, the formation of zones called areas occurs. internal stress. During heating and further sharp cooling, the stress zones are redistributed. As a result of such changes, the inner layers retain the characteristics of a liquid body, remaining viscous, while the outer layers become much stronger when compared with plain glass that have not been quenched.

When applying point impacts to the end zones, the next redistribution of the existing stresses occurs. Due to microcracks, the integrity of the sheet is broken, so that if mishandled, even the weakest blow will lead to extensive webs of cracks. different sizes. Glass will simply collapse at the slightest external effort. This principle is the basis of glass for cars: they are easily broken by a sharp blow with a sharp object. The film makes the glass safety: it holds the fragments and does not allow them to harm the driver.

In this way, tempered glass obtains its special properties directly from the tempering process. According to the technology, the material is first cut into the desired pieces, holes are made, the shape is set, and only after that it is hardened. Experts recommend refraining from further mechanical processing. However, if you are serious and categorical, first prepare the tools and remember important nuances cutting tempered glass.

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Preparing for cutting: important points

In the hands of an inexperienced craftsman who wants to cut tempered glass, the product will instantly shatter into many fragments. The only one effective option- cutting with a laser. However, at home it is hardly possible to find such a device. Therefore, we will have to go the other way, which requires preliminary annealing of the glass. Instructions will be given below.

It is important to take into account the fact that as the reannealed glass cools, its outer part will cool faster than the inner part. If the glass surface has already cooled down, this does not at all confirm the readiness of the inner part of the material. Due to the slow cooling of the glass, the formation of a large number stresses. This makes it possible to cut more High Quality. This moment must be taken into account when cutting tempered glass yourself.

To complete this difficult job, you will need the following:

1. Direct tempered glass.
2. Warm water.
3. Bake.
4. Temperature controller. The presence of this element is desirable, but you can do without it.
5. Marker.
6. Square.
7. Grinding stone.
8. glass cutter
9. Wooden rod. A product with a diameter of 6 mm will suffice.
10. Protective glasses.

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Step by Step Instructions for Cutting Tempered Glass

Cutting tempered glass requires pre-annealing this material. The process includes uniform heating of tempered glass. The main task of this stage is to eliminate the stresses that appeared in the material during the previous hardening. It is these stresses that are the main obstacle to cutting safety glass. Get rid of them - you can realize what you planned.

Annealing is performed in the following order. First, the glass is soaked in water at a constant temperature. It is necessary to soak until the temperature corresponding to the viscosity in the furnace unit is reached. It equals η = 1013 Poise. The time required for soaking depends on how large a piece of glass you are going to cut.

Example 2. Tempered glass cutting technology.

Glass brands Bullseye, Effetre and Lauscha are soaked at a temperature of +504 degrees Celsius. Borosilicate glass requires a higher soak temperature, +566 degrees. And for glass brand Satake optimum temperature is +477 degrees. It takes an average of 20 minutes to soak small beads. Larger beads must be aged for an hour. Paperweight big size kept for 12 hours or more. Especially large products weighing 40 kg or more in some situations require hardening for a period of several months.

The glass must be gradually cooled to a temperature below the deformation temperature. It equals η = 1014.5 Poise. The process must be carried out quite slowly so that no additional stresses arise. Glass brand Satake cooled at a temperature of +399 degrees Celsius. For cooling products of other brands, a temperature equal to +427 degrees is suitable. The glass must be cooled in the furnace until room temperature.

Put on your goggles and start cutting the annealed glass. Take a square, mark the cut line. The square must be kept along the left line. Cut along the line with a glass cutter. Press with medium force, making a scratch along the marking line. It is allowed to draw only 1 time along the line.

Next, you need to take a wooden rod 6 mm in diameter, put it under the cut line and apply a quick and sharp pressing force on both sides. If done correctly, the glass will break into 2 neat pieces. The edges of the resulting parts must be processed with a grinding stone. This will make the product more durable and safer.

If desired, the glass is re-tempered. It is better if this work is done by a professional. The procedure requires the appropriate skills and special equipment, so a beginner simply cannot cope with it.

Since the process of cutting tempered glass, which in practice is cutting annealed glass, is multi-step, you can simplify your task by buying plain glass, cutting off the desired sections from it, or preparing the desired holes and tempering. This will save money, effort and time.

A thermostat was mentioned in the list of necessary tools and fixtures. It is needed to maintain the temperature in the oven at a constant level. You can do without it, but it's easier with it.

Thus, cutting tempered glass is very difficult. If you don't want to spoil ready product, it is better to order a new tempered glass or cut the usual material, and then perform or order its tempering. Successful work!

Glass cutting is carried out mainly in production, but it happens that such a need arises at home. Of course, it is very good if a person cuts glass at least once in his life, but what about those who do not even have a clue how to cut tempered glass?

To cut glass, you need to purchase a glass cutter, outwardly it is very similar to a can opener. In production, special, equipped tables are used for cutting tempered glass, and in living conditions you can use normal dinner table, having previously covered it with a thin cloth.

The glass you are going to cut must be clean and dry, and you must also determine its thickness by eye. The cutting must be carried out parallel to the long side of the glass, if you have a factory cut sheet for processing, then please note Special attention at the corners, as they are likely to be uneven. This important fact must be taken into account, so be sure to check the correct angles.

If your frame is very skewed, then before cutting it is necessary to mark the diagonal run. Marking is done with ink, pencils (4M, 5M) or a marker on the reverse side. If you need glass for window bindings, then the size of the glass should be three millimeters smaller than the distance between the folds of the frame (the folds are called the recess in the frame under the glass). Such a gap is made so that when swelling or heating window frame the glass was not subject to strong stress. Over time, glass becomes brittle, so cutting must be done carefully and after lubricating the glass with turpentine.

Before cutting glass, let's decide what is tempered glass. Tempered glass is called, which is several times stronger than ordinary glass, it can be tempered several times at high temperatures, and therefore can withstand heavy loads (300 kg per sq.m.). Such glass can only be broken by a strong blow with a blunt or sharp object.

Glass is cut using an eight-millimeter ruler, this is necessary so that the glass cutter does not slip off your hands during cutting. If there is no ruler at hand, then you can use any flat rail, because, as you know, wood does not slide on glass. So, we apply the ruler to the glass, but not exactly to the markup, but leaving room for the glass cutter, and start cutting. There are two types of glass cutter - roller and diamond. A diamond glass cutter cuts better, but for cutting a corrugated sheet, it is better to use a roller one.

The quality of the tool matters, but what matters more is the virtuosity of the craftsman who will cut the glass. Not unimportant when cutting glass is the table, it must have a perfectly flat surface and the glass on it must fit the entire plane.

If you are new to glass cutting, there are a few important things to keep in mind.

1. tempered glass must be dry before cutting.
2. glass must be moistened with turpentine. And then wipe dry (this eliminates greasy spots and fingerprints).
3. the cut is carried out at one impulse, without taking your hands off the glass, otherwise the glass will crack incorrectly.

Rules for working with a diamond glass cutter: the glass cutter must be held vertically, the side with the diamond inclusion mark must be turned towards the glass, the line is drawn without pressure. It is impossible to draw a glass cutter along the marking line several times, if you are not sure that you will get an even cut the first time, it is better to practice on small pieces of glass. If the strip is obtained with fine glass dust, then you pressed hard and the glass does not heat up properly, if you still need to cut again, then step back from the first cut a few millimeters and make a second one.

It is necessary to cut the glass quickly and preferably at a time, the pressure on the glass and the speed of the glass cutter must be the same. When cutting, pay attention to the sound, it should be thin, without growling and squeaking. Also, when working with a glass cutter, it is necessary to take care of your eyes, since if chipping occurs and during blows with a hammer, small fragments can get into your eyes. It should be remembered that a break can occur at any time, so it is necessary to support the glass so that it does not fall on your feet. When the crack goes all over the glass, it is pushed up to the cut lines so that the cut line and the edge of the glass coincide, and then it is bent.

Cutting tempered (high-strength, safety, heat-resistant) glass is not a quick and difficult process, it requires quite serious preparation. Cutting it according to the same principle as usual will not work due to its high mechanical strength. During the hardening process, the material changes its structure. The matter is further complicated by the fact that “safe” glass, with all its remarkable strength qualities, is a very fragile material. When you try to cut it in the usual way, it will simply crumble into separate pieces. Let's talk in the article about how to cut tempered glass at home.

How is tempered glass made?

Tempered glass differs from ordinary glass in that after heating to a temperature of approximately 660 degrees, it is quickly cooled by blowing cold air. It is rapid cooling that underlies the process called quenching.

Features of tempered glass are:

• High level of mechanical strength.
• Security. The material breaks into large non-sharp fragments and is not traumatic.
• Resistant to high temperatures.

Due to these characteristics, these materials are widely used in construction, in the production of display cases or dishes, and in the automotive industry.

Important! This glass also has a disadvantage. Even a weak blow from the end of the glass sheet is enough, and it breaks. This feature is used by designers (creating the effect “ broken glass” in the manufacture of bedside tables or countertops). As a rule, glass surfaces in this case are arranged in 3 layers (whole - broken - whole).

Cutting order

If the sheet has big sizes, then you should not try to cut it yourself. Cutting such a product without sad consequences is possible only with the help of a laser machine. Naturally, this is not feasible in everyday life. Only correct option how to cut heat-resistant glass at home is the repeated annealing of glass. Let's consider it in more detail.

Tools for the job

Before cutting tempered glass at home, prepare necessary tools and fixtures. So, you will need:

• A special oven with the ability to heat up to 700 degrees or more.

Important! There were many such ovens in the laboratories of research institutes, which in the 90s were literally closed in batches. If there is no such furnace, you can order it at the forge (like a blacksmith).

• Thermometer with a high (the same 700 degrees) threshold.

Important! Laboratory ovens have a built-in thermostat and thermometer.

• A set of devices for marking (markers, squares, rulers).
• Grinding stones.
• Wood rods.
• Diamond glass cutter.
• Powerful fan.
• Water.

Important! You need to work in protective equipment - overalls, goggles.

Preparation, cutting of tempered glass at home

So, the only way to cut tempered glass at home is to make it less durable. Annealing helps to eliminate the stress that appeared during hardening. It is produced according to the following algorithm:

• Soak glass in water. Then gradually increase the temperature of the water to the numbers, equal to temperature viscosity in the oven (1013 Poise).

Important! Glasses of different brands have different viscosity values. In addition, the duration of the procedure is affected by the size of the sheet. For example, the duration of soaking window panes varies from 12 to 16 hours.

• Heating the glass in the oven to the incandescent temperature. For various brands, it is 470-680 degrees (Celsius). The numbers you need can be found in the documentation for the glass.

Important! Manufacturing companies from the USA indicate the temperature in Fahrenheit. To convert to the usual degrees Celsius, you must use the formula: TF \u003d TC x 9 / 5 + 32 or reference tables.

• Once the temperature has reached the desired peak, remove and cool the glass. In this case, it is necessary that the cooling be as slow as possible.
• When the glass sheet reaches room temperature, mark the cut lines on it. After the manipulations, the glass ceased to be “safe”, “tempered”, but turned into ordinary.
• Make a groove along a pre-marked line with a glass cutter, and then beat off “everything superfluous” with careful blows. To make the cut more accurate, place wooden rods under the “groove” made.
• Is the glass cut? Now is the time to temper it again. Repeat the first 2 points of the described technology exactly.
• The cooling process during glass tempering must be fast. To do this, pre-install a powerful ventilation device in the room. You can lower the air temperature up to 10 degrees, but ventilation unit is still necessary. It is necessary to blow both sides of the sheet. After the sheet temperature has reached room temperature, the procedure can be considered completed.

Before cutting tempered glass, it is worth preparing everything you need. The process requires precision and attention, otherwise the material can break into hundreds of small pieces.

What you need to know - we study the properties of glass

The first feature that makes tempered glass very popular is its increased strength. It is successfully used for loggias and balconies. This material serves as a raw material for the manufacture of translucent structures and furniture. But for all this, a large number of expensive lasers are used, and experienced specialists work on the stack itself. What to do when the material needs to be cut at home? First of all, you need to study its properties.

Essentially, glass is a thermally polished material. For its production, polished and unpolished glass sheets are used. For hardening, the material is placed in specially prepared furnaces. Inside the unit, it heats up to about 670 °C. Under such conditions, the upper layers of glass become softer. Immediately after the required temperature has been reached, the glass is cooled. First of all, the upper parts of the material cool down. In this case, the inner zones are subject to strong stress and are compressed. After such processing, the material becomes more durable and heat-resistant.

Tempered material is 7 times stronger than ordinary glass. It is quite difficult to damage the surface after hardening, unless, of course, this is done intentionally. Even in cases where the material does break, it shatters into small pieces with blunt edges. That is, even getting hurt on broken glass is quite difficult. All stages of preparation, including edge processing, are carried out during the production of the material. After that, the glass is sent to the furnace for heat treatment. At the end of hardening, it cannot be subjected to any changes. In cases where it is necessary to change the shape of the material, annealing is done.

There are quite a few areas of application for this material. Glass after tempering is often used in the construction and production of window and doorways. Shower cabins and other similar structures are made from this material. The great demand for glass makes more and more people learn how to work with it.

Can glass be cut after it has been tempered?

Despite the opinions of some "specialists", it is really possible to cut glass after tempering. However, in order for the work to be successful, it is necessary to carefully prepare for its implementation. To break the glass, it is enough just to hit it hard. But to give it desired shape, it will take much more effort and spend a lot of time.

Due to the peculiarities of the production technology, zones are formed on the glass, which are usually called internal stress areas. During heating and further cooling, these regions are redistributed. As a result, the layers inside become like liquid body with a certain viscosity. The outer layers, on the contrary, become more solid and durable. If point impacts are applied to the ends of the glass, the stresses are redistributed. Due to the appearance of microcracks, the structure is broken. In order not to violate the integrity of the sheet, it must be handled with extreme care.

This principle can be observed in cases of accidents: the glass of the car literally shatters from being hit by a sharp object. The film helps to make car glass safer. Tempered glass acquires all its characteristics when tempered. According to the technology, first the material is cut into the necessary parts, holes are made in them, and only after that they begin to harden. Many experts advise not to process the material further. However, if it becomes necessary to cut an already hardened material, then this can be done by adhering to certain recommendations.

Preparation for work - what tools are needed?

Often, in the hands of beginners, hardened material becomes unusable precisely because of haste and lack of experience. In such cases, the only right option can be called a laser, but not everyone can afford to buy such a device. In this regard, you will have to look for another way out. Many experts advise to work by the preliminary annealing method. This will allow you to accurately cut the glass and use it for its intended purpose.

It is necessary to take into account the feature that when the annealed material is cooled, its outer side will cool much faster than the inside. If the surface has completely cooled down, this does not mean that the inside is ready for cutting. Due to the fact that the glass cools slowly, the appearance of a large amount of stress in it is prevented. Because of this, it is possible to obtain a better cut. This is worth considering every time you want to cut material.

In order to do the job correctly, you need to prepare the following tools and materials:

• a piece of tempered glass;
• warm clean water;
• bake;
• a thermostat, however, if it is not there, then you can cut the material without it;
• square;
• marker;
• grinding stone;
• glass cutter;
• a wooden rod with a diameter of not more than 6 mm;
• goggles for protection.

Having prepared everything you need, get to work. In the process of cutting, follow the safety rules so as not to damage the skin of the hands and face.

Cutting material - a detailed algorithm for beginners

To cut glass evenly, it will need to be annealed. This process involves uniform heating of the surface of the material. Thus, it will be possible to eliminate the stress that was formed as a result of hardening. It is the stresses that become the main obstacles for accurate cutting of the material. It is necessary to carry out annealing in a certain order. First, heat the water and maintain its temperature. After that, the glass is dipped into the liquid until it itself heats up to a certain temperature. Different grades require specific temperatures to cut.

Yes, brand material Effetre and Bullseye must be heated to 504°C. A higher temperature requires borosilicate material, which must be dipped in water up to a temperature of 567 °C. Brand glass Satake requires less heating - approximately 470 ° C. To soak a small bead, on average, it will take no more than 30 minutes. Larger beads should be kept in water for about an hour. The paperweight requires 12 hours of soaking. The largest products, whose weight exceeds 50 kg, sometimes need to be kept in boiling water for several months.

Once desired temperature reached, cool the material slowly. The final temperature of the finished glass should be slightly below the temperature limit at which the glass is deformed. This figure is on average 1014.5 Poise. Do all the work very slowly to avoid the slightest tension. For cooling, an oven is required in which the temperature of the material must drop to room temperature. After the glass has cooled, put on your goggles and start cutting it. To do this, take a square and outline the incision line.

Hold the tool along the line you left. Cut with a glass cutter along this line. We press the material with medium force and make a shallow scratch along the marking line.

Be extremely careful, as you can only run the glass cutter along the line once. At the next stage, you need to take the rod, place it exactly under the notch line and make a sharp push to both sides of the glass. If you did everything exactly according to the algorithm, then the material will break into two neat, even parts. In order for the cut lines to be safe, they need to be processed with a grinding stone.

If there is time and desire, then the glass can be tempered again. However, it is best to trust a specialist who has both the skills and equipment for this. Due to the fact that the process of cutting tempered glass is quite long and complicated, many go the other way. They buy ordinary glass, cut it into the right pieces, and then take it to professionals for tempering.

tempered glass

Waterjet cutting can cut any type of glass:

• reinforced glass
• mirror glass
• triplex (laminated glass)
• fire resistant glass
• borosilicate glass
• armored glass
• laminated glass
• float glass
• Patterned rolling glass

and many other types.

We are approached a lot for cutting already tempered glass, we want to upset such customers, such glass as tempered or still have stemalite (tempered glass with enamel applied) is not cut by any technology, including waterjet cutting. Initially, the product is made, all the necessary cutouts are cut out by waterjet cutting, and only then the product is sent for hardening. If dimensional errors have been made and this can be corrected by trimming the increase in size, then in the case of tempering the glass only needs to be redone.

Strained glass- usually sheet glass, obtained by heating to a tempering temperature (650-680 ° C) followed by rapid uniform cooling with cold air from both sides. As a result of such treatment, residual compressive stresses are formed in the surface layers of the glass, providing its increased mechanical strength, heat resistance, and safety in case of destruction. When broken, such glass breaks into many small fragments with blunt edges that are not capable of causing serious injury. This effect is proof of the high impact strength of this glass. Since the evenly distributed impact energy, over a relatively long time, forms very small microcracks in the glass, allowing small fragments to be obtained. Thus, tempered glass has three main useful properties, each of which has its own purpose in the industry.

The safety and mechanical strength of tempered glass is used in construction, glassware, psychiatry, shop windows, hockey rink fencing, furniture, automotive and railway industries. Such a property as heat resistance makes it possible to glaze buildings without the risk of thermal shock, especially for glass tinted in mass. The only weak point of such sheet glass is the vulnerability to impacts in the butt, since in this place the residual stresses can easily be released and break the glass as a whole. Although a similar effect is often used in design (example: three-layer countertops or doors with the effect of “broken glass”)

Tempered glass cannot be cut, drilled or otherwise machined.

In the automotive industry, tempered glass is used to make side or rear windows. The use of tempered glass as a windshield is strictly prohibited (small, though not sharp, fragments can damage the eyes of the driver or passengers). For the production of windshields, silicate glass triplex is used. Although tempered glass triplexes are much stronger, they have the disadvantage of rapid and complete loss of transparency from strong impacts, which, however, does not prevent their use in architecture. Tempered automotive glass is marked English word"Tempered" - "tempered glass" or the letter "T".

In the USSR it was known as "Stalinite" (in honor of Stalin).