The assortment of the modern construction market is rich: in specialized stores you can. Metal, wood, plastic, combined - all entrance doors have special specifics in terms of manufacturing. The desire to independently make a metal door block arises for a number of reasons. For example, you want to get a design with specific requirements and additional materials, you need a high quality product at a minimum cost.
Tools and materials
Making a metal door with your own hands actually refers to a budget option: creating a product yourself will cost much cheaper than buying a finished structure. Of course, to make a truly functional and stylish door, you need to own a tool and have some experience in welding.
In addition, you will need competent blueprints, quality materials, and professional tools. Let's list the main components that are used in the process of creating a metal door composition:
Photo: door perimeter seal
The list of the above materials and tools required to create a metal door is approximate: the final solution depends on the type and functional value of the future structure. For example, when making a vestibule or entrance door, it is best to purchase a thick metal sheet. You can also use two sheets of metal: in this case, the space between them must be filled with insulation.
A metal workbench table will be very useful
Another interesting material for making a door, although not an entrance one, is.
Step-by-step manufacturing instructions
The creation of a metal door consists of four main stages: the manufacture of the frame, the production of the metal sheet, the installation of fittings and the sheathing of the product. A typical door structure is two meters high and 90 cm wide.
Consider the features of working on creating a metal door:
- Frame ... It is necessary to start making the frame after all measurements have been taken. The dimensions of the door frame should be optimal: the metal frame should harmoniously fit into the doorway, therefore, a gap of 2 cm should be left on each side.
- Canvas ... Gaps should also be left between the frame and the metal sheet, while the sheets should protrude slightly from the edges of the frame. It is necessary to carry out welding work in small areas. The seams are made no more than 4 cm in length, while the distance between adjacent seams should not exceed 20 cm.
- Fittings ... For the production of hinges, steel rods with a diameter of 2 cm are used. The hinges are welded to the canvas and the metal frame at the same time. Professionals recommend carrying out mandatory anti-corrosion treatment of the product: with its help, the door will serve for more than a dozen years.
- Cladding ... You can use any material you like: vinyl leather, PVC film, artificial leather, leatherette and others.
The main steps in making a metal door with your own hands:
- Measure the opening and leave about 2 cm from the walls to the box in order to eliminate all cracks with foam. In addition, such a gap will correct the door installation in the event of a skewed opening.
- Cut a metal corner according to the selected dimensions (approximate dimensions - 50x25 mm) and place it on the welding table. Measure the length of the diagonals of the rectangle: they must be equal. Welding can only be started if all dimensions are the same. This is how the door frame is made.
- Measure the finished box along the inside, taking into account the 1 cm gap on each side of the structure around the perimeter. Cut a corner with dimensions of 40 * 25 cm for the canvas.In the lock profile, use a grinder to make a small slot at the optimum level for installing the lock.
- At the same time, wooden slats of optimal dimensions are hammered into the metal profile. This is done to simplify the facing work.
- Also, for the convenience of welding, it is recommended to immediately weld the loop profile to the metal box and hinges. It is necessary to ensure a perfect match of the hinges and the door frame: for this, the distance between them is carefully checked. If this condition is met, it will be easy to hang the door.
- It is necessary to check: whether the profiles of the door leaf and the frame are parallel, after which the remaining profiles of the door leaf are inserted and welded into the latter.
- Then a sheet of metal is welded. First, the canvas is measured: on each side, the door should be closed by 10 mm, while on both sides of the lock - 15 mm. The sheet is cut according to the dimensions taken into account, laid on the product from the profiles.
- First, the loop is welded from the back of the sheet in the inner cavity, then the sheet is welded around the perimeter.
- A false strip is welded on the inside of the metal sheet. For better strengthening of the door structure, special stiffening ribs can be welded.
- Clean the welds and paint the product. It is recommended to paint the door even if you will later cover it. Additional coating will prevent corrosion.
- Install two locks. For this, a hole is drilled in the corner for the entry of the crossbar, then a slot is formed for fastening the lock in the metal sheet. You can also cut a hole for the door lock.
- Carry out the door trim. It can be sheathed with wooden planks or panels, glued with a PVC film that repeats the wood texture, or, for example, used leatherette. Many people simply paint the canvas and then weld interesting forged decorative elements to it. You can also use curly metal sheets or soft elements.
Material in the topic. Read directly in our review.
Modern steel door structures are not an extremely reliable protection of a building, but also an element of the interior and exterior. The steel block technology is quite remarkable, which is worth considering.
Steel door blocks: essential equipment for starting a business
Steel metal systems in a reversal
The main attribute of each building lies in the presence of a reliable overlap of the entrance. It is worth discussing the production process of the stages of manufacturing iron structures.
So each manufacturer is trying to make the manufacture of steel doors more modernized, and developers in modern times use exclusively metal blocks to block the entrance to new buildings. Today, manufacturers are trying to improve not only the technical indicators of systems, but the aesthetic side of the product from a design point of view in relation to the latest trends in interior stylistic fashion.
The business of producing iron structures is not particularly complicated, therefore any entrepreneur can give life to such a production. So the list of necessary equipment for production purposes can be accommodated in a single table:
| № | Equipment | Hardware Notes | Cost of equipment |
| Steel sheet (metal) cutting machine | Laser or plasma can be used, since cutting on such machines occurs quickly and evenly | From $ 1,800.00 | |
| Metal bending press (bending machine) | From $ 11,200.00 | ||
| Welding complex for finishing and spot welding | It is permissible to use conventional machines or specialized welding machines | From $ 1,600.00 | |
| Installation for powder coating of products: for preparing the block surface for painting | It could be a special spray booth | From $ 980.00 | |
| Installation for powder coating of products: a compressor for painting, a painting gun and a polymerization chamber (oven) | Instead of the polymerization stage, the surface can be coated after painting with two layers of special vandal-resistant varnishes. | From $ 2,400.00 |
The above list of equipment refers to the minimum required equipment. So on
Structure making machine
ready-made complete lines for the production of steel blocks are available on the world market, where all the above machines and installations are combined. Typical production lines can be fully automated or partially, when a human hand must be applied to a certain stage.
Such automated lines are often produced in the world by foreign manufacturers and are endowed with the following list of equipment:
- Plasma metal cutting installation;
- Press for bending metal sheets;
- Automatic machine for coordinate welding of door leaves;
- Two machines for welding process with jig pliers;
- Two points of the final welding process taking place in a special environment (carbon dioxide).
A typical line does not provide for the presence of a spray booth, which is equipped separately. The line capacity is reduced to the production of 10 blocks in one hour of time, but also under the supervision of at least 10 people. The approximate cost of such a continuous production process in assembled form is reduced to no more, no less, but $ 100 thousand.
Workshops for the manufacture of metal structures
Workshop for the manufacture of metal structures
At the moment, the manufacture of steel doors is carried out according to various technologies, but in fact all of them are endowed with the same initial aspects. The main part of the production technology processes should take place in separate rooms, therefore the area must provide for the presence of the following workshops:
- A workshop where metal is received and raw materials are prepared;
- Workshop where metal sheets are processed and profiles are rolled;
- The workshop where the welding and assembly process is performed (production line);
- Workshop for painting products;
- Finishing and decorative shop, provided that the finishing material is produced on the territory of the enterprise, and not purchased ready-made;
- Assembly control shop, where blocks are completed with locking and other mechanisms;
- Warehouses for storing finished products.
Each of the shops must meet specific fire safety requirements. So the premises should be finished (floors, walls), at least, with non-combustible materials, and equipped with supply and exhaust ventilation.
Production and technological process of manufacturing steel blocks
The manufacture of iron doors in relation to the technology provides for a certain sequence of production actions, which are spelled out in specialized documentation (route or technological map), which indicates:
- Basic requirements for the original quality of the material used;
- Rules for the transportation of raw materials and finished products, material acceptance and storage of input blocks;
- The special requirements documentation specifies a set of technical requirements for each stage of the process;
- Methods of quality control and control are prescribed;
- Many technical conditions (production specifications) are indicated, which were drawn up in accordance with the indications of GOST 31173-2003.
The main technological stages of the manufacture of steel structures:
Preparation of raw materials.
At this stage, the metal material must be sorted. The marking of the sheets is verified, the presence of deformations is checked, which appear mainly after the process of transportation or rolling. At this stage, scale and corrosion are also removed from the material. Storage of rolled metal in warehouses should be carried out on racks or sheets are stacked.
Marking and cutting of blanks.
The manufacture of doors starts with the correct cutting of metal sheets relative to the templates applied to the surface using scribes and center punching tools.
Processing of blanks and parts.
The door frame profile is created on sheet bending equipment.
Blanks for future input blocks are sawed to remove burrs and irregularities. So in the process, the surface layer of steel is removed at the cutting points. Sawdust can be carried out manually using simple files, as well as on specialized sawdust machines.
The processed workpieces are sent to a stamping machine, on which holes of the most diverse diameters are made in the details for the needs of installation on the structure of fittings and locking systems.
Assembly process and welding
The door leaf is assembled using resistance welding. Typical welding technology eliminates deformation damage to the door leafs and ensures complete elimination of welds on the surface.
Locking systems are installed on metal structures simultaneously with the installation of stiffeners, in areas reinforced with metal plates. A kind of technological pockets are being created. At this stage, the canvases are insulated. A non-combustible soundproofing and insulating material is laid inside the canvases.
The hinges to the assembled product are often welded manually.
Paintwork.
After completing the assembly of the structure, the block is painted. The compositions are applied exclusively to a sanded, cleaned, degreased surface. There are several methods of application:
- Jet overflow;
- Pneumatic spraying;
- Spraying in an electrostatic field.
For the process, one of several paints in a variety of colors can be used:
- Powder;
- Nitro;
- Hammer;
- Graphite.
Decorative finishing of structures.
Often, metal doors are decorated with protective coatings, molded, laminated finishing panels. Decorative finishing by production can be purchased ready-made. The following can be used as cladding:
- Dermatine, leather, vinyl leather;
- Lining made of wood;
- MDF panels, chipboard;
- Natural wood;
- Thermal foil with imitation of natural wood or monochromatic;
- Elements of decorative forging;
- Natural wood veneer.
Installation of fittings, locking systems.
Often times, fittings are cut by hand. To avoid the characteristic metallic sounds emanating from the structure of the entrance blocks, and for thermal insulation properties, the door leaves are pasted over with special shock-absorbing materials:
- Rubber seals;
- Made of rubber;
- Silicone seals.
Over the years, metal doors have performed many different functions: they reliably protect premises, decorate the entrance area of residential and public premises. Installation of high-quality metal doors is a guarantee of safety, an increase in heat and sound insulation in the space.
For many years, the demand for entrance doors with a metal base remains high, however, the choice of a reliable and high-quality product should, as before, be given great attention, despite the huge range of various offers on the modern market. After all, a metal door is the face of an apartment, house, commercial enterprise and other objects. Its appearance influences the first impression of the owners and the entire living space. Therefore, one should also not forget about the aesthetic qualities of doors, their professional installation and compliance with the conditions for further operation of the finished product.
The main types of modern metal doors
Modern manufacturers offer a wide range of metal doors for various functional purposes and configurations, with different performance properties. All models of metal doors offered today can be divided into the following types:
- technical;
- apartment doors (for household use);
- ceremonial.
All types have their own distinctive properties, aesthetic and operational characteristics.
Technical doors... This type of metal door, which is designed for use in difficult weather and operating conditions (with significant temperature changes, high humidity, fire hazard, etc.). The main qualities of these products are increased wear resistance, high functionality and mechanical strength. In the production of metal doors for technical purposes, special alloys, reliable finishing materials, as well as special coatings that protect the structure from corrosion are used.
Currently, the technical models of doors are represented by the following products:
- Vestibule doors (economy class);
- Fireproof constructions;
- Doors for equipping attics, basements, entrances;
- Internal doors to premises that are under increased control (accounting, cash desk, archive, storage, certain types of warehouses, etc.).
Apartment doors (for household use). This group includes doors for apartments, offices and other residential and commercial properties that are in the middle price category. This type of door can have a different set of security devices, a wide variety of finishes and must necessarily have good heat and sound insulation. The price category of apartment doors is mainly determined by two positions - decorative design and the reliability of protective devices. Currently, modern manufacturers offer metal doors in this market segment in various categories, from economy class to business level.
Front doors. This category of metal doors includes products of non-standard configuration and exclusive decorative design. Front door models can consist of two or three canvases, equipped with forged and stained glass elements, mirrors and luxury glass, luxurious handles and unique locking systems. Such products are installed outside or inside premises and, in addition to protection, they must provide a harmonious decoration of the exterior and interior. This is very important for various high-profile establishments - luxury villas and estates, restaurants, clubs, public and commercial buildings. Elite metal doors are distinguished not only by their unique magnificent design, but also by their impeccable quality.
Metal door selection technology
When choosing metal doors, you must first evaluate the quality and functional properties of the products. All purchased metal doors must be different:
- Durability. This indicator is provided by many factors: the quality of all materials used in the production, the company's reputation, the availability of quality certificates and warranties.
- Burglary resistance... Products must have maximum resistance to various mechanical influences. Modern robbers and thieves are very rich in different inventions. Reinforced structure, well-placed stiffeners, reliable and durable locking mechanisms, high-quality bolts, filling the door frame with stable solutions - will guarantee durability and a high level of protection. The minimum thickness of the metal sheet must be 2 mm, the product must be securely fastened and equipped with the most modern locking systems. High-quality modern metal doors are also a reliable door frame, which is a single all-metal structure.
- Functionality... Quality doors must guarantee an optimal level of sound and thermal insulation. This indicator is achieved by specifically filling the door frame with noise-insulating and insulating materials. It is important that metal doors have the following qualities: fire resistance, bulletproofness and other protective properties.
- Ergonomic... Comfortable, convenient door locking, easy-to-use fittings, well-chosen accessories - these are the essential qualities of a good metal door. And of course, each door should have optimal dimensions, easy opening, etc.
- Beautiful design and decorativeness... The appearance of metal doors should be in harmony with the style of the exterior and interior of an apartment or house. The modern choice of finishing materials and technologies allows you to choose the most suitable option for any design and architectural solution.
Despite the wide range of offered metal doors, there are still difficulties in choosing. After all, it is very difficult to distinguish low-quality products behind the catchy finish. Therefore, there are a number of key points that need attention before purchasing a product.
Metal doors are divided into 13 protection classes... The most popular apartment doors belong to the fourth class of protection. When choosing, you need to pay attention to the fact that on high-quality products there should be no gaps between the door frame and the leaf. To increase the protection of the castle structures, different armor plates and additional reinforcing plates should be used.
One of the weak points of a metal door is the seam between the outer sheet (metal) and the frame. The structure should not come off the frame so that you can easily get to the lock. Also an important factor is the thickness of the sheathing. If a sheet of metal is attached to the box with an overlap, it cannot be thinner than 2-2.5 mm, so that the protruding part of the canvas in the area of the narthex cannot be bent and get to the crossbars of the locking device. The inner metal sheet increases rigidity, but at the same time makes the structure heavier, increases the load on the door hinges, frame and its fastening. In this case, you need to strengthen these nodes.
An important indicator of resistance to burglary and significant loads during operation is the location and number of stiffeners. The minimum allowed the following number of profiles - two horizontal and three vertical and two horizontal. If a narrow profile (40-50 mm) is used, at least three horizontal and five vertical stiffeners are required. Today, it is rare to find indicators of the number of stiffeners at the manufacturer's stand, but you can check this indicator with a consultant of the manufacturer or seller of a metal door.
To prevent the door from being removed, at least three special anti-removable pins should be built into the structure, preferably located closer to the corners of the doors. To fill the gap between the frame of the structure and the opening into which the frame will be inserted, cover strips are needed, which are welded to the door frame. Cover strips will make it harder for thieves and intruders who want to knock down a metal door.
Another important element of the door is the hinge. When installed, they are selected for each model individually, taking into account their massiveness and size of the structure. The best for metal doors are bearing hinges, which ensure that the massive door opens easily and without sagging.
Major manufacturers and brands. Prices and quality, difference
Currently, there are about 30 major suppliers of metal doors on the market. The most popular are the products of the following companies: "Bastion", "Bars", "Bel-Ka", "Guardian", "Geometry of Metal", "Sesame", "Strizh", "Torex", "Jaguar - M" and others. We can also mention the companies that are representatives of the factories "Lyon" and "PANPAN", as well as firms that cooperate with many factories and constantly change manufacturers and suppliers depending on the quality and cost of the supplied products.
Models of metal doors offered by manufacturers today are distinguished by price segment, by configuration and level of security. The cost is formed, among other things, from the additional complete set of the door: fittings, lock, cylinder, panel, and also increases the price of manufacturing non-standard door sizes.
Now, large firms, as well as their official representatives in the regions and small artels, are engaged in the production of metal doors, so the cost of an ordinary product can vary from 4,000 to 25,000 rubles, while "elite doors" can cost from 40,000 to 150,000 rubles. and higher. Naturally, it should be understood that the doors in the price segment are less than 7000 rubles. have minimal protective properties.
Currently there are the following product price segments:
- up to RUB 10,000 (segment of economy class). Such doors have minimal security systems, with standard fittings, a cylinder and a lock with an average security code. Such a door is resistant to some burglary methods and, in combination with other methods, can serve as good property protection.
- up to 20,000 rubles (class standard). Such designs are equipped with more complex locking mechanisms, high-quality locks and beautiful fittings. Optimal in a combination of price-quality-safety.
- up to 40,000 rubles (Business Class). You can feel completely safe behind such products. They are equipped with the most modern security systems, high-quality beautiful fittings, brand locks of the highest level.
- over 40,000 rubles (elite class). These are top models of doors, consisting of new, innovative developments, maximum security, cylinders and locks with the highest secrecy. Hardware with a high degree of protection and elegant design.
Foreign manufacturers of metal doors are represented by the following manufacturers:
- Chinese doors
- Little-known companies mainly manufacturing products for a narrow market
- Brands that are known all over the world
Chinese doors are the most famous product today. Such doors are very cheap, have an attractive appearance, but the quality of the products, as a rule, leaves much to be desired. Naturally, this does not apply to all metal doors made in China, they also have high-quality doors, but the domestic market is filled mainly with cheap offers.
Little-known foreign companies are not of great interest to the mass buyer, as a rule, they are purchased at exhibitions or on the advice of a designer.
Doors from branded manufacturers are a great way to purchase quality products. Such doors combine many unique features, embody all the latest developments in protection and security. The only drawback of all foreign models is the binding to standard sizes.
Construction of metal doors
The main elements of door construction are divided into the following groups:
- Finishing
- Canvas and box elements
- Fittings
- Mounting accessories and materials.
The main components of metal doors are a frame and a leaf, which are connected together by welding. The structural elements of the box and the canvas include: a canvas, a double narthex, a bearing profile, an inset envelope, a solid counter-removal, pins, hinges, protective parts under the crossbars of locks, door sound insulation and its insulation.
Depending on the profile used, the door structure is divided into profile and bent-welded. Door constructions made using the bent-welded method are distinguished by a high price, however, in comparison with other products, they are the most reliable and durable. Profile doors, as a rule, do not have "wings" at the joints, therefore, to protect the seam between the door frame and the wall, special platbands are installed.
Depending on the number of metal sheets, door structures are single-sheet, double-sheet and three-sheet. Single-leaf doors do not have an inner sheet of metal; they are installed without platbands, since the frame structure itself already has steel platbands. Products with two sheets need to be fitted with platbands.
Locking systems for metal doors
Traditionally, all types of locks are subdivided into several classes. For example, a first class lock is a locking mechanism designed for interior doors. The locking system of the third or fourth class already guarantees good reliability and durability of the lock. The manufacturer assumes that a professional burglar will spend at least half an hour to open a fourth-class lock. Therefore, when purchasing a door or agreeing on its configuration, it is necessary to ask the manufacturer about the class of the lock to be installed in the product.
To increase the reliability and protective functions of metal doors, modern manufacturers install two types of locking systems in them: cylinder and lever.
Cylinder locks it is usually customary to call English locks, in which there are larvae with pins, thanks to which unique secrecy is achieved in the mechanism. The larvae are subdivided into one-sided and two-sided. In the one-sided version, the lock opens only from one side, respectively, the two-sided larvae allow you to open the door from either side. The obvious disadvantage of a cylinder lock is that it is not very resistant to impacts that can damage the lock. To avoid this disadvantage, special overlays are used. High-quality larvae rotate around their axis. So, if a potential thief with a portable drill visits the house, he will not be able to drill a grub that will constantly spin.
Lever locks equipped with special levers, which open the locking mechanism. Such locks have a high security class. Lever systems equipped with a special manganese insert, which is installed between the door and the lock body, have the highest security class. Such an insert is necessary in order for the intruder's drill to break when drilling the lock.
You should also pay attention to the quality and quantity of the pins and crossbars of the doorway. The cheapest models have up to three crossbars, the more expensive ones have four or more. These protective elements are made of high-strength alloy steel and are equipped with metal cylinders on top, which make them difficult to cut.
Additionally, metal doors can be supplied with latches of various types, from traditional models to modern innovative mechanisms.
Heat and sound insulation of a metal door
Modern manufacturers are constantly increasing the range of heat-insulating and sound-proof materials used for insulating metal doors. Mineral wool and polyurethane remain the most common for insulation.
- Mineral wool Is a fibrous material with an excellent fire safety indicator. It is environmentally friendly and safe. Doors insulated with this material have good heat and sound insulating properties.
- Polyurethane has excellent performance properties. Doors insulated with this material do an excellent job with the negative effects of cold. The indicator of low thermal conductivity of polyurethane guarantees the preservation of the standard temperature regime in the premises. Does not make the door structure heavier and the lightness of the material.
A two-circuit system of high-quality seals eliminates the penetration of drafts and dust into the premises, provides a standard level of sound and thermal insulation. For metal entrance doors in private houses, cottages and other facilities, effective panels with polyurethane foam with a reflective surface, additional linings and even electric heating systems can be used to eliminate cold bridges.
The sound insulation of the doors will be almost absolute if, when closed, there are no gaps between the leaf and the frame. For these purposes, manufacturers use various seals:
- silicone (with a plastic rib);
- made of foam rubber (with a fixing adhesive base);
- magnetic.
In this article:
For the house to be a real 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 solid steel are a standard requirement that every man in the street makes to his own home today.
Despite the fact that competition in the entrance door market is quite high, you can still find a niche here: recently, the demand has grown not only for the quality and reliability of door leaves, but also for a spectacular appearance (especially in elite new buildings, well-guarded entrances and cottage settlements ). Therefore, having thought over an interesting, stylish design and an assortment range of several models, you can enter the average price niche on a par with branded manufacturers.
However, as practice shows, the decisive factor when buying from 80% of consumers is the price. Therefore, even "garage production" - with the help of hand tools and machine tools, is quite capable of making a profit in the shortest possible time, which will allow you to step on the next stage of business development.
- GOST 31173-2003: Steel door blocks. Technical conditions;
- GOST 23118-99 Steel building structures;
- GOST 5089-97: Locks and latches for doors. Technical conditions.
Equipment for the production of steel doors
1. Automatic lines
They are used in large factories with high productivity from 200 doors / day and more. The technological process is fully automated; it takes about 2 minutes to make one door leaf. High-precision technology ensures the same geometry of the product, the formation of profiles, the drilling of holes for fittings and fasteners, the painting of the door leaf and the filling of internal voids - everything happens automatically, with minimal manual intervention.
Welding of the product is also automated, thanks to the use of special welding robots... Strong weld joints do not require additional cleaning and grinding by hand.
Pros:
automated lines allow the production of 500-600 finished products per day with minimal risk of rejects.
Minuses: high price and cost of maintenance (the 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 m 2), where, in addition to the workshop itself, it is necessary to provide for significant areas for storing raw materials and finished products.
2. Lines-semiautomatic (using manual labor)
A set of equipment and machines for opening a partially automated production:
- Semi-automatic guillotine or metal cutting machine (plasma - Fig. 4, laser) - from 120,000 rubles;
- Press brake - 70,000 rubles;
- Welding machines (include spot welding, door leaves, welding with pliers, final welding in carbon dioxide) - from 100,000 rubles. Can be replaced with conventional welding machines;
- Painting equipment (spray gun, compressor).
Rice. 4 (Plasma)
This equipment can produce 15-20 doors per day. The required area of the premises is at least 250 m 2.
Pros: quite elevated cost 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 with simpler equipment, which will significantly reduce start-up capital, but 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 rejects. In addition, highly qualified masters, trained to work both on machine tools and manually, will be required to ensure the correct execution of production technology at all its stages.
3. Manual labor and machine tools
Minimum set of equipment:
- Bulgarian;
- mechanical guillotine for metal cutting (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 m 2).
Minuses: 2-3 doors per day is the maximum productivity for such equipment. Such mini-production can be focused only on the low price segment. To avoid a large number of rejects, specialists who know how to work in metal are needed.
Workshop for the manufacture of metal doors
All basic processes of steel door manufacturing technology should be carried out in separate rooms. Therefore, the production area should provide for:
- workshop for acceptance and preparation of metal;
- workshop for processing steel sheets and rolled profiles;
- assembly and welding shop;
- paint shop;
- decorative and finishing (and if the finishing is made directly at the enterprise, and not purchased ready-made, then a separate room for the technological line for its production) (Fig. 7);
- assembly and control shop;
- finished goods warehouse.
Special requirements include the presence of a fire safety system, decoration of walls and floors with non-combustible materials, good ventilation.
Technological process for the production of metal doors
The technology for manufacturing 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;
- a sequential process of converting raw materials into a steel door block, painting and assembling it;
- a set of technical requirements for each process;
- methods of control and quality control;
- method of transportation, storage of finished products and other technical conditions (TU production), which are drawn up in accordance with the requirements of GOST 31173-2003.
The main stages of the technological process for the production of steel doors
1. Preparation of metal
Before going to production, the metal is sorted. The marking is checked, the presence of deformations after rolling or transportation, corrosion and scale are removed. At the warehouse of raw materials and materials, rolled metal is stored stacked or on stable racks (at least 2.5 m high).
2. Marking and cutting of workpieces
The production of doors begins with cutting sheet metal according to patterns drawn with center pins and drawing patterns. For cutting metal rolling use:
- mechanical equipment (guillotine shears, presses, saws);
- oxygen method (cutting on stationary machines with gas cutting or hand cutters);
- laser, plasma cutting.
3. Processing of workpieces
The profile for the door frame is made on bending equipment, where under the pressure of the press a metal plate is given a shape bent at the required angle.
It can be either a standard rectangular design or an arched model. In the second case, the arcuate profile of the upper part of the door is passed through a rolling machine to shape it into the desired shape. After rolling, the profile is cut into the required parts.
The workpieces are sawed off - to eliminate irregularities and burrs, the top layer of metal is removed in the places of cutting. Sawdust is carried out manually, using files or on special sawdust machines. After processing, the workpieces 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 assembly of the door leaf is carried out using contact welding, which eliminates deformation of the door leaf and ensures that there are no welding seams. The sheets are welded to the frame, 15-20 mm of indentation is left on the front side, which will serve as a bridging. In the manufacture of metal doors, a multi-seam type of welding is used. The tightness of the construction of the canvas is achieved through the installation of special stiffeners.
Door locks are installed simultaneously with stiffening ribs, in places reinforced with metal plates (the so-called "technological pockets"). A non-combustible basalt slab is used between the door leaves as a seal and a sound insulator (alternative options: wood, mineral wool, glass wool, polyurethane foam, polypropylene).
The hinges are manually welded to the assembled door, observing the necessary gaps between the door leaf and the door frame. The assembly is carried out according to several types (according to markings, in conductors, according to 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 pouring;
- pneumatic spraying (fig. 13);
- by spraying in an electrostatic field.
Nitro, powder, graphite, hammer paint of various colors is used - this coating forms a good protection that protects the door from corrosion and light mechanical damage. After drying, the thickness of the applied layer is monitored and the absence of visual defects - air bubbles, unpainted areas, cracks, streaks.
6. Sheathing with decorative elements
To impart high wear resistance and an original decorative effect, an additional protective coating can be applied to the surface of the workpiece - molded or laminated finishing panels, which are manufactured at the enterprise by cutting (automatic or semi-automatic) according to ready-made templates or purchased as workpieces.
Types of skins:
- leather, leatherette, vinyl leather;
- wooden lining;
- Chipboard;
- natural wood;
- monochromatic thermal film or with imitation of wood of various species;
- forging elements;
- veneer.
7. Installation of locks, fittings, quality control of the finished product
Fittings are cut in and the locks are checked manually. To avoid the characteristic knock of metal on metal when the door is closed, to enhance heat and sound insulation, a special shock-absorbing material is glued to the door leaf - a rubber seal made of rubber or silicone.
To control the assembly quality and the tightness of the door leaf to the box, the finished product is placed on a control stand. If all requirements are met, the door is packed 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 the method of electric arc welding;
- roll forming - using bent rolled profiles.
Today, the second technology is most successfully used in production, where finished metal sheets are the raw material for the manufacture of doors. Many people believe that the thicker the steel sheet in a metal door, the better. And this is not entirely true. Too heavy doors can lead to a lot of problems, for example, difficulty in opening / closing due to heavy weight, rapid wear of the hinges due to high loads. Therefore, 2 mm is the top "strip" for standard apartment doors. Each additional millimeter adds about 8 kg of weight.
Required fittings:
- 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-plant for the production of steel entrance doors. The target group of consumers is construction companies and private households.
2. For the legal registration of the business, an LLC was created on the general taxation 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".
For the production of metal doors and the provision of services for their installation, you must issue a license in accordance with SNiP 11-23-81. The cost of processing a package of documents and obtaining a license is about 35,000 rubles.
3. The production workshop is planned to be located on 100 m 2 of non-residential rented premises. The rental price is 15,000 rubles / month.
4. Costs for the purchase of equipment - 125,000 rubles:
- guillotine crank shears НК3418А;
- 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 with a size of 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 wheels, grinding - 420 rubles;
- primer - 4 l * 87 rubles = 348 rubles;
- solvent - 2l * 210 rubles = 420 rubles;
- paint - 2 kg * 460 rubles = 960 rubles.
Total: 7081.80 rubles
6. Income from sales
It is planned to manufacture and install 3 doors per day with a 21-day working day. The selling price of the product was established by a comparative analysis of prices in the market and is equal to 12,500 rubles. Installation cost - 1200 rubles.
Forecasted revenue per month: 63 items * 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 - 5750 rubles;
- advertising - 15,000 rubles;
- staff salary (director, 5 workers and sales manager) - 65,000 rubles;
- payroll taxes –24,375 rubles;
- income tax - 58,124.32 rubles.
Total: 184,449.32 rubles / 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.
The choice of the front door is a rather crucial moment, since the safety of all the property of the house or apartment, and sometimes the life of the owners, will depend on its design. Today, the assortment of specialized stores is formed by many manufacturers, presenting their products, which have a wide range of prices - from the most modest to very high. Therefore, you can always choose a door that will fully meet the capabilities of homeowners.
The purpose of the front door is not only to protect the home from intruders, as it must prevent the penetration of external noise and cold air masses. In addition, there are models that can create a reliable barrier even to an intense flame during a fire. How to choose an entrance metal door professional advice - they are necessarily given depending on where it will be installed: at the entrance to an apartment or a private house, as well as taking into account many criteria that directly affect the performance of this design.
Front door selection criteria
To clarify all the nuances, we turned to the Moscow manufacturer of entrance doors "ProfMaster" company, where more than 80% of orders are individual production "to order", because this is the only way to find a door without compromising on quality.
There is a list of the main points that you need to pay special attention to when purchasing an entrance door:
- Place of installation. The door can be installed on the street in a private house or at the entrance to an apartment, that is, in an entrance room protected from direct external influences. The choice of insulation material and external cladding will depend on this.
- Protection level. Several aspects can be attributed to this criterion at once:
- the thickness of the metal used to make the door;
- frame design;
- the number of metal layers in the door leaf;
- the number of stiffeners inside the canvas frame;
- the number and design of locks and hinges;
- the presence of an overview element.
- Insulation material. In order to prevent the door from letting in cold masses and extraneous noise, it is insulated with mineral wool, polystyrene foam, polyurethane foam or cardboard. In some cheap models, insulation may be absent altogether.
- Number of seals. They can be installed on a door leaf or frame, in one, two or even three rows. For fire-resistant structures, sealing circuits made of special materials are used.
- Door weight. A high-quality product should be heavy, as it has reliable stiffeners and is made of high-quality, sufficiently thick metal sheet.
- A design solution that will harmoniously fit the door into the overall design of the facade, if the door is to be installed in a private house.
- Fire-fighting qualities of materials, if you plan to purchase a door that has protection against the spread of flame.
- Vandal-proof coating - especially necessary if there are animals in the house that can scratch the door lining, or in an apartment where there is no combination lock at the entrance to the entrance.
- The door must have a quality certificate or a product passport, which will indicate all of its characteristics.
Assessment of the main characteristics of the doors
The price of such products is quite high, but you can be sure of the security that they will fully provide. Therefore, in recent years, more and more apartment residents and home owners prefer this particular door option.
So, the design of the entrance doors must fully meet all the criteria for safety and comfort when opening and closing it, as well as satisfy the homeowners in terms of its design. Therefore, when making a choice, you need to compile a list of the requirements for the door structure in advance, and if the model meets them, then this option is ideal for a specific entrance to a building or apartment.