Help on Tele2, tariffs, questions

The popularity of steel entrance structures is largely due to their impressive performance and aesthetic parameters. However, achieving such characteristics is far from easy and is only possible with careful adherence to the quality of work at all technological stages production. Its final stage is the assembly of metal doors. It is obvious that the production of a reliable and durable product is simply impossible without proper installation individual elements, parts and components into a single design.

Sequence of manufacturing steel doors

With all the importance technological operations, occurring when the metal door is assembled and welded, the manufacturing process begins much earlier. It consists of several sequential actions, on each of which the success of the final result depends.

Technologically, the production of a steel entrance structure consists of the following main stages:

• preparatory work:

1. creating a general sketch and design of the product;
2. development of each individual element, part and unit;
3. writing software for CNC machines

• production:

1. preparation of steel sheets of the required size;
2. making holes for hinges, locks and other components on CNC machines;
3. production on a stamping press of basic load-bearing elements structures, which include the frame, racks, stiffeners and racks;

• assembly of metal entrance doors;
• finishing of products ready for installation.

Each of the operations described above is a complex technological process, which, in turn, can also be divided into sequentially performed actions. It is necessary to take into account that the above diagram assumes the manufacture of a standard input structure. If you need to produce a metal door of non-standard dimensions, even more operations are required.

Main stages of the assembly process

Assembling a metal door is deservedly considered one of the most responsible and significant stages of production. It is performed in two stages:

• installation of individual elements and structural parts into a single product;
• the so-called straightening, which involves giving the product a marketable appearance before finishing.

In the first stage, it is first collected load-bearing frame steel structure, which ends with the installation of stiffeners and welding of the web. Next, locks and other protective devices, for example, anti-removal pins, are installed. Then the internal cavity of the sash and, if necessary, the elements of the frame are filled with insulation, which at the same time acts as sound insulation. After this, the canvas is sheathed with two steel sheets, and at the end of the stage, the front elements and parts of the product are installed.

At the straightening stage, which always ends the assembly of a metal entrance door, welds and joints of structural parts are processed, scale is also removed, surfaces are leveled, and burrs are removed. After this, the product is ready for finishing.

Necessary equipment

A prerequisite for the assembly of a metal entrance door to be completed successfully and with proper quality is the use of modern high-precision equipment. The key to effective operation of almost all the most serious domestic companies Those involved in the production of steel entrance structures are constantly improving the technologies used, which is simply impossible without regular modernization of machines and other tools.

Moreover, in addition to the already mentioned CNC equipment, many Russian companies use semi-automatic production lines for the assembly of steel water structures. They usually consist of:

• a machine designed for cutting metal;
• powerful welding machine;
• special press brake.

To work on such semi-automatic high-precision equipment requires high qualifications and good training of personnel, the presence of which is another prerequisite release competitive in modern construction market products.

In this article:

For a house to truly be a fortress, the entrance to it must be blocked by reliable metal doors - protection from uninvited guests, cold winds and street noise. Entrance doors made of durable steel are a standard requirement that every average person makes today for their own home.

Despite the fact that competition in the market entrance doors is quite high, you can still find a niche here: recently there has been an increase in demand not only for the quality and reliability of door leaves, but also for spectacular appearance(especially in luxury new buildings, well-guarded entrances and cottage villages). Therefore, having thought through an interesting, stylish design and an assortment of several models, you can enter the average price niche on a par with branded manufacturers.

However, as practice shows, price remains the deciding factor when purchasing for 80% of consumers. Therefore, even “garage production” - with the help hand tools and mechanical machines is quite capable of bringing profit in the shortest possible time, which will allow you to step into the next stage of business development.

• GOST 31173-2003 — Steel door blocks. Technical conditions;
• GOST 23118-99 Steel construction structures;
• GOST 5089-97 - Locks and latches for doors. Technical conditions.

Equipment for the production of steel doors

1. Automatic lines

Apply to large factories with high productivity of 200 doors/day and more. The technological process is fully automated, for the production of one door leaf takes about 2 minutes. High-precision technology ensures the same geometry of the product, the formation of profiles, drilling holes for fittings and connecting fasteners, painting the door leaf and filling internal voids - everything happens automatically, with minimal manual intervention.

Welding of the product is also automated, thanks to the use special welding robots. Strong weld joints do not require additional stripping or grinding by hand.

Pros: automated lines make it possible to produce 500-600 finished products per day with minimal risk of defects.

Minuses: high price and maintenance costs (lines are made to order, the cost starts from 6 million rubles). For the full operation of such equipment, a large production area is required (from 1500 m2), where, in addition to the workshop itself, it is necessary to provide significant areas for storing raw materials and finished products.

2. Semi-automatic lines (using manual labor)

A set of equipment and machines for opening partially automated production:

• Semi-automatic guillotine or metal cutting machine (plasma - Fig. 4, laser) - from 120,000 rubles;
• Press brake – RUB 70,000;
• Welding machines (include spot welding, door panels, welding with tongs, final welding in a carbon dioxide environment) - from 100,000 rubles. Can be replaced with conventional welding machines;
• Equipment for painting (painting gun, compressor).

Rice. 4 (Plasma)

Using such equipment it is possible to produce 15-20 doors per day. The required room area is at least 250 m2.

Pros: The cost is quite reasonable for a medium-sized business - the price of a semi-automatic line completely depends on the configuration (from 400,000 rubles). But some machines can be replaced more simple equipment, which will significantly reduce the start-up capital, but will increase the amount of manual labor and, accordingly, the cost of wages to workers.

Minuses: « human factor“—the less automation, the higher the number of defects. In addition, highly qualified craftsmen will be required, trained to work both on machines and manually, to ensure that the production technology is carried out correctly at all its stages.

3. Manual labor and mechanical machines

Minimum set of equipment:

• Bulgarian;
• mechanical guillotine for cutting metal (Fig. 5);
• milling machine;
• lathe;
• auxiliary hand tool.

Pros: minimum costs for the purchase of equipment (from 60,000 rubles) and rental of premises (60-80 m2).

Minuses: 2-3 doors per day is the maximum productivity for such equipment. Such mini-production can only be aimed at low price segment. To avoid large quantity defects, specialists who can work with metal are needed.

Workshop for the production of metal doors

All basic manufacturing processes steel doors must be carried out in separate rooms. Therefore, the production area should include:

• metal acceptance and preparation workshop;
• workshop for processing steel sheets and rolling profiles;
• assembly and welding shop;
• paint shop;
• decorative and finishing (and if the finishing is manufactured directly at the enterprise, and not purchased in finished form– that and separate room For technological line on its production) (Fig. 7);
• assembly and control shop;
• finished goods warehouse.

Special requirements include the presence of a fire safety system, finishing of walls and floors with non-combustible materials, and good ventilation.

Technological process for the production of metal doors

The manufacturing technology of a steel door includes a certain sequence of actions prescribed in a special document (technological or route map), indicating:

• requirements for the quality of materials;
• rules for their transportation, storage and acceptance;
• sequential process of converting feedstock into steel door block, its painting and assembly;
• a set of technical requirements for each process;
• quality control and testing methods;
• method of transportation, storage of finished products and other technical specifications(production specifications), which are drawn up in accordance with the requirements of GOST 31173-2003.

Main stages technological process steel door production

1. Metal preparation

Before going to production, the metal is sorted. The markings are checked, the presence of deformations after rolling or transportation, corrosion and scale are removed. In the raw materials warehouse, rolled metal products are stored stacked or on stable racks (at least 2.5 m high).

2. Marking and cutting workpieces

Door production begins with cutting sheet metal according to patterns applied using punches and inscriptions. For cutting rolled metal use:

• mechanical equipment (guillotine shears, presses, saws);
• oxygen method (cut to stationary machines with gas cutting or hand torches);
• laser, plasma cutting.

3. Processing of workpieces

The profile for the door frame is made on bending equipment, where under pressure from a press the metal plate is given a shape bent at the required angle.

This can be either a standard rectangular design or an arched model. In the second case, the arched profile of the upper part of the door is passed through rolling machine to give the desired shape. After rolling, the profile is cut into the required parts.

The workpieces are filed - to eliminate irregularities and burrs, the top layer of metal in the cutting areas is removed. The sawdust is done manually, using files or using special sawdust machines. After processing, the blanks are sent to a stamping machine, where holes of various diameters are punched for locks and fittings in accordance with the prepared cards.

4.Assembly and welding

The door leaf is assembled using resistance welding, which eliminates the deformation of the canvas and ensures the absence of welding seams. The sheets are welded to the frame, a 15-20 mm indentation is left on the front side, which will serve as a rebate. In the manufacture of metal doors, a multi-seam type of welding is used. The density of the canvas structure is achieved through the installation of special stiffening ribs.

Door locks are installed simultaneously with the stiffeners, in places reinforced with metal plates (the so-called “technological pockets”). Non-flammable material is used between the door leaves as a seal and sound insulator. basalt slab (alternative options: tree, mineral wool, glass wool, polyurethane foam, polypropylene).

Hinges are manually welded to the assembled door, maintaining the required gaps between the leaf and the door frame. Assembly is carried out using several types (by marking, in jigs, by copiers) and is controlled at each stage for compliance with the geometry in order to correct the defect if necessary.

5. Treatment with paints and varnishes

After assembly, the door blank is sent for painting. The paint is applied to a cleaned, sanded and degreased surface in one of the following ways:

• jet dousing;
• pneumatic spraying (Fig. 13);
• spraying in an electrostatic field.

Nitro, powder, graphite, and hammer paint of various colors are used - this coating forms good protection, protecting the door from corrosion and light mechanical damage. After drying, the thickness of the applied layer is checked and there are no visual defects - air bubbles, unpainted areas, cracks, stains.

6. Covering with decorative elements

To impart high wear resistance and an original decorative effect, additional protective covering– molded or laminated finishing panels, which are manufactured at the enterprise by cutting (automatic or semi-automatic) according to ready-made templates or purchased in the form of blanks.

Types of cladding:

• leather, leatherette, vinyl leather;
• wooden lining;
• laminated chipboard;
• natural wood;
• thermal film, plain or with imitation wood of various species;
• forging elements;
• veneer.

7. Installation of locks, fittings, quality control of the finished product

The fittings are inserted and the locks are checked manually. To avoid the characteristic knock of metal on metal when closing the door, to enhance heat and noise insulation, a special shock-absorbing material is glued to the door leaf - a rubber seal made of rubber or silicone.

To control the quality of assembly and the tightness of the door leaf to the frame ready product installed on a control stand. If all requirements are met, the door is packaged and sent to the finished product warehouse.

Raw materials for making steel doors

There are two technologies for manufacturing steel doors:

• pipe-coal, using rolled pipes fastened by electric arc welding;
• roll forming - using bent rolled profiles.

Today, the second technology is most successfully used in production, where the raw materials for the manufacture of doors are ready-made sheets of rolled metal. Many people believe that the thicker steel sheet in a metal door, the better. And this is not entirely true. Doors that are too heavy can lead to a lot of problems, for example, difficulty opening/closing due to heavy weight, rapid wear of hinges due to high load. Therefore, 2 mm is the upper “bar” for standard apartment doors. Each additional millimeter adds about 8 kg of weight.

Required accessories:

• locks;
• loops;
• latches/latches;
• pens;
• additional (closers, eyes, clamps, blocking devices).

Business plan for the production of metal doors

1. It is planned to open a mini-factory for the production of steel entrance doors. Target consumer group – construction organizations and private households.

2. For legal registration business LLC was created on the general tax system indicating the following types of OKVED:

• 28.75.21 “Production of armored or reinforced safes, fireproof cabinets and doors”;
• 45.25.4 “Installation of metal building structures.”

To produce metal doors and provide services for their installation, it is necessary to obtain a license in accordance with SNiP 11-23-81. The cost of completing packages of documents and obtaining a license is about 35,000 rubles.

3. Manufacturing facility it is planned to be located on 100 m 2 of non-residential rented premises. Rental cost – 15,000 rubles/month.

4. Costs for the purchase of equipment - 125,000 rubles:

• guillotine crank shears NK3418A;
• sheet bending mechanism MGL-2500;
• drilling machine 2116K;
• abrasive cutting machine;
• welding machine TDM-403;
• spray gun;
• Bulgarian;
• additional equipment (hand tools, racks, exhibition stand).

5. Calculation of the cost of 1 product - a metal door measuring 2180 * 1040 mm.

• sheet steel 2mm – 0.098 t * 31,600 rubles = 3096.80 rubles;
• insulation (mineral wool) – 0.2 m 3 * 1475 rubles = 295 rubles.
• electrodes – 4 kg * 43 rubles = 172 rubles;
• mortise lock – 820 rubles;
• hinges, handle, peephole – 550 rubles;
• cutting and grinding wheels – 420 rubles;
• primer – 4 l * 87 rubles = 348 rubles;
• solvent – ​​2l * 210 rubles = 420 rubles;
• paint – 2 kg * 460 rubles = 960 rubles.

Total: RUB 7,081.80

6. Income from sales

It is planned to manufacture and install 3 doors per day with a 21-day workday. The selling price of the product is determined by the method of comparative analysis prices on the market and is equal to 12,500 rubles. Installation cost – 1200 rubles.

Projected monthly revenue: 63 pieces * 13,700 rubles = 863,100 rubles/month.

Material costs – 63 pieces * 7081.8 rubles = 446,153.4 rubles/month.

7. Other costs of doing business:

• rent – ​​15,000 rubles;
• electricity – 1200 rubles;
• depreciation of fixed assets – 5,750 rubles;
• advertising – 15,000 rubles;
• staff salary (director, 5 workers and sales manager) – 65,000 rubles;
• salary taxes – 24,375 rubles;
• income tax – 58,124.32 rubles.

Total: RUB 184,449.32/month.

8. Financial results

Net profit: 863,100 rubles - 446,153.4 rubles - 184,449.32 rubles = 232,497.28 rubles/month.

The initial investment (equipment + license + material costs for 1 month of work + other costs) will pay off in 4 months of work.

For owners of apartments in which there is something valuable, one day the question arises of strengthening their home. The most obvious and simple solution In such a situation, a reliable door will be installed. There are a lot of varieties of metal entrance doors on sale and it is quite difficult to immediately navigate all this variety. What type of steel door to choose, how they differ - these questions will be answered in this article.

Characteristics of metal entrance doors

All metal doors, regardless of their class, are much stronger and safer than wooden ones. This truth is not disputed by anyone. But they differ quite greatly in characteristics from each other.

• security - this means how long a metal door can resist attempts to break into it;
• comfort - except protective properties, steel doors are also chosen for such qualities as excellent sound insulation and fire protection;
• reliability - the quality of any metal door is determined by its service life, ease of use and protection against damage;
• aesthetics is another property according to which a choice is made, because it will be in his house or apartment, and therefore must be in harmony with the interior.

All of the above qualities are important when choosing a metal door. But very often one of them prevails over the others, and some is practically absent.

Properties of metal doors

All metal doors are made of high-strength and stainless materials. Basically, cold-rolled alloy steel is used in their production.

The internal design of the doors is very similar for all classes. It is a door leaf consisting of metal frame, which is made from iron corners, steel bent profile, the same profile pipes. Then flat steel sheets are welded to the finished frame, and the cavity between them is filled with various cushioning materials. This can be foam rubber, polypropylene plates, mineral wool or natural wood. All-metal doors are rarely made, usually in cases where they are used to protect a safe room and premises such as a bank vault, cash register, etc. These doors are called armored. The thickness of the metal used in steel doors varies.

Structure of a metal door

1 external door trim; 2 steel sheet; 3 heat and soundproofing material; 4 door frame made of metal profile; 5 steel sheet; 6 finishing inside door leaf; 7 platband; 8 reinforced steel frame; 9 peepholes; 10 fittings; 11 loops; 12 blockers; 13 internal valve; 14 locks; 15 rubber seal; 16 anchors.

Hinges in steel doors are made using special technologies. They must meet the requirement of holding a lot of weight. The door frame is one of the largest parts, not counting the door leaf. The closing device in metal doors is located in a security pocket, this is done in order to increase protection and increase reliability against certain hacking methods. An essential part of a steel door is stiffening ribs, which maintain the shape of the door and prevent it from deforming from impacts.

The basis of any metal door is special profile and a sheet made of steel are structural elements responsible for strength and reliability. The seal used inside the door leaf is responsible for comfort and sound insulation. This component of the door also affects the retention of heat inside the apartment.

Basic installation steps

Tools required when installing a metal door:

• measuring instruments (tape tape, level);
• hammer;
• electric drill;
• a set of keys and a screwdriver.

The installation steps can be broken down into the following steps:

• preparation of the opening, which consists of removing interfering pieces of mortar and other debris;
• installing a door in an opening that was prepared in advance;
• fixing the frame by level. To do this, you will need wedges that are installed between the steel frame and the wall;
• then, using an electric hammer drill, holes are made in the wall for anchor bolts;

• insert anchor bolts, and their fixation with nuts;
• filling the gaps between the frame and the wall with foam or a special solution;

• removing the protective coating from the door leaf.

Metal door classes

According to the price criterion, doors are divided into economy class - cheap, premium class - expensive and high quality, and elite - the most expensive and exclusive.

Economy class metal doors

The economy class includes metal doors, the main purpose of which is to protect a house or apartment combined with a low price. They are distinguished by a simplified design and lower quality. The cost of such a metal door can also be reduced by saving on exterior decoration. Most often, powder coating, inexpensive laminate and other cheap materials are used, but despite this, the door can look quite decent.

Due to compliance with their production technology, this group of doors has good sound insulation, heat resistance and blocks the entry of unpleasant odors. Chinese economy class metal doors are available to a wide range of consumers.

Premium metal doors

The premium class includes steel doors characterized by the following features: sophisticated design, high quality structural elements and a correspondingly high price. When finishing these doors, more expensive materials are used - high-quality lining, complex powder coating, expensive laminate. Premium steel doors offer less wear, provide greater security, and have a sophisticated design.

Elite metal doors

Elite doors are very expensive, as they are made from expensive materials. In their production we use only high-quality locks and fittings from the best manufacturers. Excellent design, developed in accordance with the customer’s interior - these are the hallmarks of the highest cost group of doors. These doors make the most of natural materials, expensive finishing, additional armor linings. Luxury doors are usually only available to wealthy people.

Separately on this list are doors made by non-professionals, the so-called “handicraft” method. They are sometimes offered by folk craftsmen. They are made in garages, using a welding machine and circular saw. They are made of very thick and cheap metal, but do not contain seals or interlayers that would increase sound insulation.

What to consider when choosing a metal door

When choosing a steel door for yourself, a person focuses on such indicators and factors as price, burglary resistance, durability, maintenance cost, visual appeal, ease of use, heat resistance, sound and heat insulation. But the importance of these factors varies depending on where the door will be installed and how much money is available to purchase it.

Steel doors that suit a person in most respects may be too expensive. The opposite situation will lead to the purchase of an unreliable metal door. All manufacturers claim that their metal doors are reliable and burglar-resistant. But in fact, the difference between the time required for a professional to open a metal door of an inexpensive and an expensive category is about 6 minutes. The simplest metal doors in this regard open in just a couple of minutes, and those considered impregnable - in 8. And the difference in price ranges from ten to twenty thousand rubles. So how to make the right choice?

The best method to protect yourself from a thief is to install an apartment alarm in addition to the door.

The response time of security agency employees should be taken into account when choosing a door based on the criterion of resistance to burglary - it should be enough for the timely appearance of security.

If the main criterion is the appearance of the door, then it is best to focus on the interior and furnishings of your apartment and the harmony of the door with the facade of the building. In this case, the use of combined cladding and detailed design would be appropriate. These services are currently provided by many enterprises engaged in the production of steel doors on a professional basis.

Official division of locks for metal doors into classes

Door lock - here's another one the most important detail steel door design, which is characteristic of absolutely all of their types. The classification of metal doors according to the degree of security provided depends on the installed lock. According to GOST 5089-97, which is called “Locks and latches for doors,” the state establishes four classes of locks.

Let's look at them in more detail:

• The first class includes locking devices that have very low performance resistance to burglary. It is believed that they do not pose any obstacles to theft due to their low strength qualities;

• suitable for second grade locking mechanisms, whose security characteristics are at the usual level, and whose strength properties are below average. GOST sets the time required to open such a lock without keys. It is about five minutes;
• the third type of locks has the most high qualities protection and the average strength of the materials included in them. The specified time for breaking them is ten minutes;
• the last variety is the fourth class. They have high security properties and are made from special durable materials and resist opening for about half an hour.

When determining the opening time, we had in mind the work time of a high-class burglar with special tool. An ordinary person rarely manages to open even a second or first class lock.

Classification of doors by degree of security, type of coating and dimensions

Classification by safety level

By analogy with the classes of locks, metal doors also differ. Based on their reliability and burglary resistance properties, they can be divided into three categories:

• ordinary - they are equipped with locks of 3-4 classes and blocking devices and obstacles to removal. These include metal entrance doors of economy class;
• reinforced steel doors - also contain class 3-4 locks inside, are equipped with locks that prevent them from being removed, the hinges of such doors are reinforced, and the perimeter is closed with multi-bolt locks. Most often, premium metal entrance doors have this protection;
• security metal doors - have the properties of the previous types, but additionally prevent opening by pressing, squeezing and other similar moments.

Classification by type of coating

If we consider the classification of doors by type of coating, they can be divided into the following groups.

Metal doors with transfer coating. It provides a more attractive appearance, being bright and aesthetic. Often this type of coating imitates others. Perfect for use in places protected from moisture and sun.

The Teflon coating is black, which gives the door a strict and discreet look. This coating material is practically scratch-resistant and does not fade when exposed to ultraviolet radiation. Teflon is an excellent coating for doors that are installed in country houses and are in contact with the street.

Auto enamel coating. Special technology that helps achieve a balance between quality and visual appeal. These doors can be installed in apartments and houses.

Hammer-transfer coating - on one side, such a door is covered with a hammer method, which makes it resistant to scratches, chips, etc. On the home side, the coating is transfer, which allows you to choose it in accordance with the interior.

Dimensions and methods of opening metal doors

Door dimensions are also taken into account when classifying them. Distinguish standard sizes and custom-made doors.

Based on the number of locks, metal doors are divided into one- and two-lock. Elite doors are usually made with two or more locks.

According to the method of opening, doors are divided into right-hand and left-hand. There are doors that open 90 degrees, others can open 180.

What to look for when choosing metal doors

• Average size door frame is 2000x800 mm, which does not always correspond to the size of the doorway in a particular case. Therefore, the height and width of the opening are first measured, and only then is it purchased or (if non-standard size) door is ordered;
• thermal insulation in the door leaf should be made of foam plastic or mineral wool, and installed around the perimeter rubber seals. You can often stumble upon a trick from the manufacturer when he writes that the door has batting insulation on both sides. This means that under the sheathing on both sides there is a layer of batting only 5 mm thick, which is clearly not enough for heat and sound insulation;

• When purchasing cheap Chinese metal doors of economy class, the base price includes only the black color of the finishing coating. Please note that you will have to pay extra for any other color;
• The quality of the door is also indicated by the locks installed on it. Most budget models are equipped with two types of locks - upper lever and lower mosrentgen Brown. At the same time, more expensive and presentable models are always placed in advertising photographs. Both of these locks are very popular due to their low price, but they do not provide the necessary protection against burglary;
• The next thing you need to pay attention to is the thickness of the door frame, which also determines the heat and sound insulation of an apartment or house. It comes standard from one profile pipe 5x2.5 cm or reinforced 7.5 cm thick.

Cost of metal doors

As mentioned above, the difference in price between classes of entrance doors is very significant. But with the right choice, you can buy a durable and reliable door even for little money.

Price for an economy class metal door

But if you want to buy not just a reliable, but also an exclusive and luxurious item, then you should choose luxury doors.

Economy class technical metal doors are used for industrial and warehouse premises.

Metal doors are made according to different technologies, albeit on the same principle. And you need to figure it out. Only in this case can you choose optimal model, without relying only on the advice of consultants in stores. Here is basic information about door production. Information and samples for the article were provided by the steel door production company T-Steel.

Equipment and materials

The materials used are sheet steel, profiles or angles different sizes and thickness, a set of components (door hardware: hinges, handles, locks, eyes, etc.). The quality of the door depends both on the strength and thickness of the steel, and on the quality of the fittings (primarily the locking mechanisms).

Materials are processed using different types of equipment:

• Automated. Such equipment is used by enterprises that produce more than 200 doors per work shift.
• Semi-automatic. These are cutting machines welders, press brakes, painting booths. With semi-automatic production, the percentage of defects is lower, but productivity is also lower - up to 17-20 products on one line.
• Mechanical. This is a set of hand tools: grinder, lathe and milling machines, special guillotine, etc. Such equipment is used extremely rarely. Enterprises often give preference to semi-automatic machines.

Automated lines allow you to produce more products per day, thereby reducing its cost. However, the percentage of defects in such enterprises is high, and if quality control is inadequate, the buyer may identify defects.

Production process

Conventionally, the production of metal doors can be divided into four stages.

1. At the first stage, the box and canvas are made. The box is the outer part of the product, which will subsequently be inserted into the doorway, and on which the canvas itself will be hung. They make it from a corner. The corners are welded or bent. The leaf is the part of the door in which the lock is installed and which performs protective functions. It is made in this way: a frame is created from a corner (stiffening ribs can be used), then a sheet of steel is welded to the frame on one or both sides.
2. At the second stage, hinges are installed on the box and the canvas, carefully checking the installation locations. Holes are made in the canvas and corners for fittings and a lock.
3. At the third stage, the product goes to spray booth where it is processed. Any metal doors need treatment, regardless of what finish they will use in the future.
4. At the fourth stage, fittings are installed and the canvas is finished inside and out. During the finishing process, the door can be insulated and seals installed.

The finished product is packaged and sent to a warehouse, and then for sale.

Doors are made to order in approximately the same way, but here the dimensions and sketch of the customer are used.

How to choose a door

Appearance, brand of door and fittings, number of locks - this is not all you need to pay attention to. Be sure to take a look or check:

1. How thick the steel was used for the door leaf. A panel that is too thin can be pierced even with a knife, while a panel that is too thick will make the door impossible to lift.
2. What is the thickness of the steel in the corners that were used for the frame and box. The strength of the structure depends on this.
3. Were sealants used and was there insulation? A door without these elements will freeze in winter and let sounds through. You can’t put it either in an apartment or in a private house.

As you can see, it is enough to know the basics of door production technology in order to choose the right model.

Available on the market armored doors Chinese-made ones in most cases only look effective. They are made from thin sheet metal, the thickness of which rarely exceeds 0.8 mm, and it can be opened with a can opener. Therefore, if you need a really durable and reliable design, it is advisable both with economic point both in terms of vision and in terms of efficiency, make it yourself.

Preparation of materials

Before starting work, it is necessary to take measurements of the doorway and sketch out a schematic drawing of the structure. With a standard width (800-900 mm), the door can be made single, but with a wider opening, it is advisable to make a prefabricated frame - an additional leaf is added to the side.

A metal door consists of 3 main components:

To make a welded door you need following materials(quantity is determined overall dimensions designs):

• Corner 50×50×5 mm – for the door frame.
• Profile square pipe 50×50 and a thickness of at least 2 m (you can use a corner of the appropriate size) - for the frame.
• Metal sheet with a thickness of 2 to 5 mm - for canvas.
• Steel hinges (2-3 pcs.) – the quantity depends on the weight of the door.
• Insulation - polystyrene foam or mineral wool.
• Lock.
• Material for decorative cladding(at the discretion of the owner) - plywood, lining, veneer, plastic panels etc.
• Consumables – electrodes (selected depending on the steel used, diameter up to 3.0 mm), grinder discs, drills.

Step-by-step manufacturing of a door frame

The dimensions of the box must be smaller than the opening - a gap of 20 mm is provided between the ends of the walls and the structure. This will allow you to adjust the position of the door and avoid distortion when installing it.

Taking into account these gaps, corners are cut and laid out in rectangular design on a flat plane ( welding table or sawhorses pre-calibrated for flatness).

The corners of the box must be 90° - checked using a carpenter's angle and measuring the length of the diagonals. The structure is welded and the welds are subsequently cleaned flush with the surface of the corners (for a tight fit of the door leaf).

Door assembly and welding

Taking into account the size of the box, blanks are prepared from square pipe for making a frame. Gaps between the frame and the door frame:

• bottom and top – 10 mm;
• from the canopy side – 5-7 mm;
• from the lock side – 6-8 mm.

As a result, the frame should be smaller internal dimensions boxes are 20 mm in height and 11-15 mm in width.

Step-by-step door leaf manufacturing technology:

1. The cut profile is laid out inside the box, the gaps are fixed (available materials are used - plates, grinder discs or wood chips of appropriate thickness) and the diagonals are checked.
2. A cutout is made in one of the side profiles for installing a lock.
3. When the diagonals match, the frame is welded and the seams are cleaned.
4. The frame and box are tacked together around the perimeter in 4-6 places.
5. Marking and cutting metal sheet. It is necessary to provide an overlap of 10-15 mm on the box, and 5 mm on the side of the canopies. Taking into account the gaps between the frame and the frame, these values ​​will be 20-25 mm on the sides and 10-12 mm on the hinge side.
6. The box and frame are placed and aligned on top of the metal sheet.
7. Welding is performed in separate seams (length within 40 mm, distance about 200 mm) staggered from the middle to the edges, alternately on different sides of the door leaf. This will prevent possible deformation of the sheet and the structure as a whole.
8. To increase the rigidity of the structure, horizontal and vertical profile blanks of a certain length are welded. In order to facilitate the decorative lining of the door, wooden blocks can be hammered and secured into the frame.

Welding door hinges and installing a lock

Before installing the hinges, the structure is turned over - the steel sheet should be on top. When installing awnings, it is important to maintain their alignment. The hinges are welded to the sheet and to the box. The tacks used to connect the box and frame are cut off with a grinder. The door opens and the awnings are scalded from the inside.

After this, all welds are thoroughly cleaned and the structure is painted. This will protect the metal from corrosion, so painting should be done regardless of whether decorative finishing is performed or not.

Places for the keyhole and handle are marked on the door leaf, and drilling is performed. The mounting holes are drilled, the threads are cut with a tap, and the lock is bolted.

Also at this stage you can prepare a hole for the peephole. It is drilled through a vertical profile in the middle of the door or is shifted slightly to the side and the opening is made only in the door leaf.

Installation of metal doors

Mounting plates (6-10 pcs.) are prepared - they can be made from the remaining scraps of the sheet that was used for the door leaf. The parts are welded to the box.

Installation steps:

1. The horizontal and vertical of the door frame is aligned. Fixation is done using wooden wedges.
2. The level of the doors is again controlled.
3. IN mounting plates and holes up to 150 mm deep are drilled in the wall for anchor bolts.
4. The top anchor is hammered in first on the side of the box where the hinges are located.
5. The level of location is checked again, and if necessary, the structure is trimmed.
6. The bottom anchor is hammered in next, and the middle one last.
7. Attaching the front part is carried out in the same sequence.
8. Metal doors are hung.
9. The gaps between the wall and the frame are filled with construction foam.

After installation, you can begin insulating the doors and finishing with the selected materials.