Reinforcement a240 what class a1 or a3 - Metals and their processing

A1 (A240) fittings: application and technical characteristics of class according to GOST 5781-82

Concrete is the most common building material. It is used in the construction of residential and office buildings, warehouses and industrial premises, dams, bridges and roads.

However, despite the fact that concrete works great in compression, even with minor bending and tensile loads it quickly collapses. To rid it of this disadvantage, a variety of fittings are widely used. A1 fittings are considered one of the most common.

What is she like? Where is it used? It will be useful to provide as detailed answers to these questions as possible.

What is she like?

Class A1 fittings fall under GOST 5781-82, which determines its appearance and characteristics.

It is a smooth metal rod. The diameter can be different - the material is available in fourteen standard sizes.

Rods with a thickness of 6 to 40 millimeters and a length of 6 to 12 meters are produced, which allows specialists to easily choose the material that is best suited for a particular job.

In some cases, by mutual agreement between the buyer and the manufacturer, the length of the rods can reach 25 meters. The weight of A1 reinforcement directly depends on the diameter. For clarity, we present several specific numbers showing the relationship between the diameter and the weight of one meter of rod:

10 millimeters - 617 grams;
16 millimeters – 1.58 kilograms;
20 millimeters – 2.47 kilograms.

Made by hot rolling. The main material used in manufacturing is carbon, and in some cases low-alloy steel (with the addition of chromium and manganese).

According to GOST, there should be no defects on the surface that reduce the performance characteristics of the material - cracks, flaws and sunsets. The only exception is a small amount of rust, traces of rolled out air bubbles, sagging and dirt.

For ease of transportation, rods with a diameter of up to 10 millimeters are supplied laid in coils, and those over 10 millimeters are supplied in the form of rods of various lengths. However, the length of the rods should not be less than 200 centimeters. If this is specified additionally, then all the material can have a certain length, which is the most convenient for a particular construction project.

The main advantages of this material are the ability to be used in aggressive environments, high strength, flexibility and durability. In total, these qualities make A1 reinforcement one of the most popular and widespread in private and industrial construction.

What is the difference between A1 and A240?

Working with reference books or simply visiting the website of manufacturers and sellers of fittings, many people are faced with the question - what is the difference between A1 fittings and A240? These materials have the same characteristics and purpose, but different names.

The difference really lies only in the name. According to the outdated classification, the material is called A1, but recently most manufacturers have been using a different name - A240 fittings. So, the requirements for the material, its diameter, length, composition and scope of application are exactly the same. We can confidently put an equal sign between these two brands.

Scope of application

The scope of application of smooth A1 reinforcement is simply enormous.

Since the material has a smooth surface without ribs, which further increase the area and quality of adhesion, it is usually used as auxiliary rods. For example, when reinforcing high-strength reinforced concrete with corrugated reinforcement, A240 is used to fasten it and form a frame.

In this case, the A240 reinforcement performs the function not so much of reinforcing concrete products, but of holding the main reinforcement in the proper places, guaranteeing the integrity of the structure.

In this form, it is used in the construction of various objects: bridges, mines, dams, high-rise buildings, airfields, tunnels and others.

Reinforcement of beams with clamps from A1 (A240) reinforcement

However, if reinforced concrete must withstand relatively small loads, smooth A1 reinforcement can be used independently. The scope is quite wide:

To reinforce panels and beams, rods with a diameter of 12 to 32 millimeters are used;
columns are reinforced with rods in the range of 14-36 millimeters;
the foundation, depending on its size and loads, with material from 10 to 40 millimeters.

Reinforcement of the foundation with smooth reinforcement

In individual construction, class A240 reinforcement with a diameter of 10-16 millimeters is most widely used.

The thinnest rods with a diameter of 6 and 8 millimeters are used as wire for tying and for reinforcing plaster, concrete floor and wall screed.

In some cases, smooth A1 reinforcement can be used to create frame and decorative metal structures and their parts.

Main advantages of the material

It is no coincidence that A240 fittings are so popular. First of all, the smooth surface greatly simplifies the joining process by welding.

Yes, such a connection is undesirable, since at the welding sites there appear areas of steel that are especially susceptible to corrosion. In addition, these areas are the weakest - under significant tensile and bending loads, they are the ones that most often fail.

Still, welded joints are widely used on construction sites. And the smooth surface of the A1 rods ensures maximum ease of operation.

The next advantage is high strength. As mentioned above, in the manufacture of A1 (A240) reinforcement, only high-carbon steel St3 is used. Its main advantage is high strength. Class A1 reinforcement made from it perfectly withstands any load - compression, bending and tension - without harm. Even under prolonged loads, the quality of the material does not decrease, and it can effectively cope with the task for many years.

If necessary, rods are made of alloy steel. 0.3% chromium and up to 0.65% manganese are added to the basic composition. Together with a carbon content of up to 0.22%, this gives the steel excellent properties. It can withstand enormous loads and better resist corrosion, increasing service life and reducing the risk of early failure.

Finally, in total, all the technical characteristics make the reinforcement a universal building material. Even when working in extreme conditions, it retains its main advantages.

Resistance to most aggressive environments makes it indispensable in the construction of ordinary residential buildings, warehouses, hangars and factories, as well as oil refineries and oil storage facilities. Most other brands cannot boast of such properties.

Even A3 reinforcement, which is more durable and expensive, is not suitable for use in such conditions - the presence of an aggressive chemical environment leads to the fact that the high-strength material deforms and cracks in the shortest possible time.

As you can see, A1 or A240 reinforcement is an excellent building material that is widely used in various fields of human activity. It will be a good choice for the construction of a huge dam and a strip foundation for a summer cottage. Combined with the affordable cost and large assortment of manufactured materials, this makes it one of the most popular.

Source: https://VseoArmature.ru/vidy/armatura-a1-a240

Armature

Reinforcement is a type of building material used for the manufacture of monolithic structures. It also has such names as: construction reinforcement, corrugated reinforcement, steel reinforcement, A3 reinforcement, A500s reinforcement.

AREAS OF APPLICATION

Construction of buildings and structures, production of reinforced concrete structures (slabs, etc.), bridge construction, production of foundations, floors of private houses, production of reinforcing mesh.

DIAMETERS AND TYPES OF PRODUCTS

Reinforcement from factories in the Russian Federation is supplied hot-rolled and cold-deformed with quality certificates, manufactured according to regulatory documents GOST 5781, GOST R52544, GOST 10884, GOST 6727, according to TU, STO ASChM 7-93. The form of delivery from factories is bars of measured and unmeasured lengths and coils (coils).

Reinforcement in coils is made with a diameter of 5 to 12 mm, internal diameter 400-900 mm, external 800-1250 mm, height 600-2000 mm, weight varies from 800 kg to 3000 kg.

Reinforcement in rods is made with a diameter of 5 to 40 mm, rod length; standard measured 6m, 9m, 11.7m, 12m and unmeasured from 4 to 11.7 meters. Manufacturing plants have the ability to produce fittings of any other length, at the request of the customer.

If we talk about the diameters most often used in construction, we can note the following sizes: 10 mm, reinforcement 12 mm, 16 mm, 25 mm.

ASSORTMENT AND CLASSIFICATION OF FITTINGS

The fittings are divided into classes and have alphanumeric designations:

A - for example A500C, AT800 where A - means hot-rolled or thermomechanically strengthened reinforcing bars. B500С where B means that this is cold-deformed reinforcing bar. C - this rolled product is weldable, the numbers 400, 500, 800 mean a yield strength of at least 400 N/mm, 500 N/mm, 800 N/mm.

Reinforcement A-I (A240) is hot-rolled steel of round section which has a smooth profile and is produced with a diameter from 6 mm to 80 mm.

Reinforcing bars of class A240 are manufactured with a diameter of up to 12 mm inclusive in coils (coils) and rods (length 6m, 9m, 11.7m, unmeasured length), reinforcement diameters from 14 to 40 are manufactured only in rods.

In the manufacture of class AI reinforcing steel, the following grades of steel are used: boiling steel St3kp, semi-quiet steel St3ps, calm steel St3sp.

Reinforcement AIII (A400) is a steel periodic profile of circular cross-section with a corrugated surface, which is manufactured according to GOST 5781-82 from structural low-alloy steel grades: steel 35GS and steel 25G2S with the addition of alloying elements such as manganese and silicon. Produced in diameters from 6 to 80 mm. In the USSR it was the main type of reinforcement used for reinforced concrete products.

The disadvantage of the reinforcement is that arc welding is prohibited for steel 35GS according to SNiP 2.03.01-84, due to a decrease in the ductility of the steel at the welding points, as a result of high heat input, which can lead to the destruction of reinforced concrete structures during the construction process.

Refusal to weld when performing construction work forces us to provide significant reserves for the cross-section of reinforcement, which leads to the use of more meters of rolled reinforcing bars and an increase in cost.

A500S reinforcement is hot-rolled thermomechanically strengthened reinforcing steel, initially manufactured according to STO ASChM 7-93 by the Severstal plant and other factories in accordance with GOST R 52544-2006. At the moment, or more precisely, since July 2016, the only regulatory document remains GOST 52544-2006, which regulates the production of steel reinforcement class A500C. Produced in diameters from 4 to 40 mm.

Compared to A400 fittings, it has a number of advantages. This is strength and flexibility due to an increased yield strength of at least 500 N/mm2. Lower cost due to the absence of alloying elements in steel. The profile does not have intersection points of longitudinal and transverse ribs, the presence of which can lead to the formation of fatigue cracks.

Increased weldability allows the use of arc welding when installing and laying reinforcement.

Profile of fittings A500SProfile of fittings A400

A500 fittings are manufactured at the Tula TMPZ plant by hot rolling from high-carbon quality steel grade 76, which is used in the manufacture of rails and complies with TU 093311-313-36554501-2014.

The following types of workpieces are used for the production of this reinforcement - a steel square or a decommissioned rail. Profile dimensions from 8 mm to 22 mm, mechanical characteristics and weight of 1 meter of length correspond to GOST 52544-2006.

The distinctive feature and disadvantages of this reinforcement is that it is laid without arc welding, that is, it is overlapped or using mechanical connections, and the cross-shaped connections of the rods are made knitted. Also, this reinforcement breaks when the bending stress exceeds 40°.

The reinforcement is used in the form of individual rods, as well as as part of knitted reinforcement frames and meshes, in monolithic reinforced concrete structures of buildings and structures of any purpose and level of responsibility in accordance with GOST 54257. The advantages of this reinforcement are that it has increased corrosion resistance compared to class A500C.

REINFORCEMENT GOSTS

GOST 10884 this GOST divides reinforcing steel into classes depending on the mechanical properties of the strength class - which corresponds to the yield strength measured in newtons per mm2 square millimeter and operational characteristics - indices C, K where C (weldable), and K (resistant to corrosion cracking) . Examples of these products are reinforcing steel: class At1200, class At1000K, class At500S, class At600, class At400S, class At600S, class At1000K, class At600K, class At800, class At800L, class At1000.

GOST 5781 This GOST subdivides steel reinforcement depending on its mechanical properties. Developed in the USSR and until recently it was the main type of reinforcement for reinforced concrete products.

Class A-I (A240), class A-II (A300), class A-III (A400), class A-IV (A600), class A-V (A800), class A-VI (A1000).

Steel reinforcement of class A-I (A240) is made only smooth, and classes A-II (A300), A-III (A400), A-IV (A600), A-V (A800) of periodic profile and smooth (at the request of the consumer ), and steel class A-VI (A1000) - only periodic profile.

GOST 52544 This GOST applies to reinforcing bars of class A500s and B500S (where A500s is hot-rolled steel without thermomechanical or other subsequent processing, and B500s is mechanically and thermomechanically strengthened rolled steel). At the moment, fittings produced in accordance with this GOST are the most common and popular in the construction industry.

TYPES OF FITTINGS

Steel reinforcement - metal

corrugated reinforcement - round reinforcement with a periodic profile: made of reinforcing steel - steels used in production are st3, 35gs, 25g2s, class a500s, a400, a500, a300, a600, a800, a1000
smooth reinforcement - has a round cross-section and a smooth profile surface: made of reinforcing steel - steel used in production is St3, class A240

Composite reinforcement - plastic

fiberglass
basalt-plastic

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Main parameters and dimensions

The nominal diameter and cross-sectional area, the weight of 1 meter of length of reinforcing bars, permissible deviations in weight relative to a linear meter must correspond to those indicated in the table.

Nominal diameter of rolled products, dн, mm	Nominal cross-sectional area Fн, mm2	Weight of rolled products 1 m long
Nominal, kg, theoretical weight/DO	Permissible deviations, %
6	28.3 Fn, mm2	TV = 0.222, DO = 0.204-0.239	±8%
8	50.3 Fn, mm2	TV = 0.395, DO = 0.363-0.426
10	78.3 Fn, mm2	TV = 0.617, DO = 0.586-0.647	±5%
12	113 Fn, mm2	TV = 0.888, DO = 0.843-0.932
14	154 Fn, mm2	TV = 1.21, DO = 1.149-1.27
16	201 Fn, mm2	TV = 1.58, DO = 1.501-1.643	±4%
18	254 Fn, mm2	TV = 2.00, DO = 1.92-2.08
20	314 Fn, mm2	TV = 2.47, TO = 2.371-2.568
22	380 Fn, mm2	TV = 2.98, DO = 2.86-3.099
25	491 Fn, mm2	TV = 3.85, TO = 3.696-4.004
28	616 Fn, mm2	TV = 4.83, DO = 4.636-5.023
32	804 Fn, mm2	TV = 6.31, DO = 6.057-6.562
36	1018 Fn, mm2	TV = 7.99, DO = 7.67-8.309
40	1256 Fn, mm2	TV = 9.86, DO = 9.465-10.254

Rebar diameters, types, classes, price per ton

Our Metal Base sells fittings and offers to buy fittings of classes a500s, 35gs, 25g2s, a500, a400, a240, at wholesale prices. We have corrugated, smooth and composite steel reinforcement in stock in any quantity.

With us you can find out the price per meter or price per ton for fittings of any type and diameter, as well as get a calculation of the cost of your order. The fittings can be purchased for delivery or pickup.

You can order metal via email, WhatsApp, feedback form and by phone.

Source: https://ros-met.com/armatura/

A240 fittings, what class and some features of the brand - Machine

03.12.2017

Steel reinforcement performs a huge number of tasks in construction, sometimes even opposite ones, but most of all it is in demand in the construction of reinforced concrete structures. Despite the apparent uniformity of reinforcing bars, they differ greatly in design features, because each concrete structure has its own types of reinforcement.

Classification

There are a huge number of operations in construction where the presence of reinforcement is mandatory. All processes are different, each has its own requirements. Therefore, even professionals cannot always say where and what kind of fittings should be used. Therefore, a classification of reinforcing bars was carried out, the purpose of which was to simplify the selection and standardize products.

Steel reinforcement is divided into classes depending on different parameters.

According to manufacturing technology, it falls into the categories of hot-rolled, cold-formed and rolled.
By profile type: corrugated and smooth. The first includes classes A2, A3, A4 and A5, the second A1.
According to operating conditions: stressed and non-stressed. In the first case of constructing a frame or reinforcing mesh, the reinforcement is tensioned, poured with concrete, and after it dries, it is released. The steel is compressed, which also compresses the concrete structure.
According to the orientation in reinforcement cages, it can be longitudinal or transverse. It is not recommended to install class A1 reinforcing bars in longitudinal rows. And it cannot be welded.

Technology for the production of cold-deformed reinforcement

Separately in the classification there is a division according to the chemical composition of the metal (steel). Three positions:

The basis is the strength class. It is divided into several positions. There are different designations for types of fittings, so sometimes consumers get confused. For example, class A1, also known as AI or A240. Accordingly, A2-AII-A300; A3-AIII-A400; A4-AIV-A500; A5-AV-A600 and so on.
Manufacturers produce thermally strengthened reinforcement, the marking of which includes the letter “t”. There are six classes here. At400, At500, At600, At800, At1000, At1200. To put it simply, during the production of reinforcing bars during hot deformation, additional rapid cooling is carried out, thereby increasing the strength characteristics of the metal.
According to the degree of oxidation: SP - calm, KP - boiling, PS - semi-quiet. The separation is based on production technology. For example, boiling steel got its name because during the pouring process gases are rapidly released from it and it boils. This is the lowest-grade steel due to the formation of a large number of pores inside from the released gas. Of the three groups, when constructing reinforcement frames and meshes, it is better to choose a calm one.

When choosing, pay attention to the reinforcement classes. They determine in which structure which reinforcement should be installed. The main parameters and characteristics of the steel profile are clearly divided into classes.

Namely, diameter, tensile strength and the source material from which the product is made. Below is a simplified table in which the parameters are scattered depending on the class of reinforcing bars.

Reinforcement class table

Class differences

In the construction industry there is such a term as mounting fittings. This group includes class A1 (the old marking, which is now being abandoned by using A240). The mounting version can only be used in non-load-bearing structures. It is prohibited to install it in the reinforcing frames of load-bearing structures. Most often it is welded.

A300 and A400 are used today in load-bearing structures of civil and industrial construction. These are common types of fittings used everywhere.

And one more point, everything related to classes from 1 to 4 refers to building reinforcement. Higher classes are considered industrial.

Additional markings

Manufacturers indicate in letters the additional properties and qualities of the product in the marking of reinforcing bars. Eg:

the letter “K” means that the rods were treated with anti-corrosion compounds;
“C” - weldable reinforcement.

Designations are placed after the digital indicator of steel fluidity in MPa. For example, grade A300C is hot-rolled reinforcement with a yield strength of 300 MPa, which can be used for welding. The letter “A” means that the steel bars are classified as hot-rolled. Cold-deformed reinforcement is marked with the letter “B”, rolled reinforcement is marked with the letter “K”.

Only type marked “C” can be welded. In reinforcement cages that will be used for load-bearing concrete structures, standard material is used.

Here, welding is not used, and the frame elements are connected with knitting wire. The strength of the connection is beyond doubt, while the wire allows the rods to move freely relative to each other within 1-2 mm.

The mobility of the frame elements does not load the joints during the process of pouring and setting of concrete.

Profile form

Class A240 has a profile in the form of a smooth rod. The rest have a corrugated surface, in which the pattern of protrusions is different. Today, manufacturers produce mainly three designs:

Ring, produced according to GOTS 57-81. This is an old Soviet standard; accordingly, most domestic manufacturers produce this type of fittings.
Crescent. It came from the West, there are rods with this pattern on the market, even some domestic factories offer this type of reinforcement. Today, factories in the CIS countries solve the problem of entering world markets taking into account the requirements of world standards. And the crescent profile is the world standard.
Mixed. This is a new approach to solving the problem associated with increasing the strength of concrete structures. The profile is used only for rods above A500.

Composite reinforcement for concrete

Today, the main division of reinforcing bars is made by the material from which they are made. Two kinds:

The second type is a modern product, which is made from fibers of different origins, filled with binder polymer compositions. Three types of fibers are used: glassy, basalt and carbon. Accordingly, the reinforcement itself is called fiberglass, basalt plastic and carbon fiber.

Fiberglass reinforcement is used more often in construction. It has high strength and low specific gravity. The main advantage is the high tensile strength. The indicator is 2.5 times higher than that of steel. Therefore, the equal replacement of steel with composite, depending on the loads, is determined by the smaller diameter: steel - 6 mm, fiberglass 3.57 mm (inner diameter).

Basalt-plastic and carbon fiber varieties are characterized by increased resistance to aggressive environments. They cost more than the first type, so glass fiber reinforcement is used more often in construction operations. Composite material has low fire resistance. Plastic begins to melt at a temperature of +160C.

Composite reinforcing bars are rarely used in the construction of foundations and other load-bearing structures. It can be used if the concrete foundation is poured onto a solid foundation that can itself withstand heavy loads.

Most often, composite models are used to reinforce brickwork, as a frame for concrete pipes and other non-load-bearing products, as meshes for cladding walls and other surfaces. They found their main application in cement screeds.

They are laid in the form of a grid, connecting the elements with knitting wire. For obvious reasons, such material cannot be welded.

Conclusion on the topic

The types of reinforcement indicated above are a classification that makes it convenient to accurately select the material to meet the necessary requirements of the structures or reinforced concrete products being constructed. Therefore, it is important to understand the types and types of reinforcing bars, especially in terms of purely appearance.

It makes it possible to determine which class the selected material belongs to. And there are many external differences, as noted above. Here is not only the type of profile, but even the diameter of the rods. All other parameters can be found in the quality certificate issued for each batch of products.

Classification of reinforcement: types, classes and groups Link to main publication

Source: https://regionvtormet.ru/stanki-i-oborudovanie/a240-armatura-kakoj-klass-i-nekotorye-osobennosti-marki.html

Reinforcement classes: A400, A240, A500C

It is difficult to imagine at least one modern house that would be created without the use of reinforcement. This material is one of the most popular and in demand in the construction industry.

It is not surprising that there are different classes and brands of fittings, and each of them is designed to perform certain tasks.

What classes are there?

Since reinforcement is used very widely in construction, there are plenty of varieties. In civil engineering, at least three classes of this material are constantly used. In industrial production, completely different goals are set, and therefore the range of materials used is much wider.

Very often people get confused about the terms or markings and cannot understand what class the fittings are A400, A3, etc. This is completely normal, because an ordinary person has no need to understand such details. However, such knowledge will definitely be useful.

It’s worth noting right away that there are several schemes by which steel is marked. There is an old traditional scheme and a new one. The old scheme was used back in Soviet times. For example, class A3 fittings are a product with old markings. And there are several of them. From models A1 to A6.

The higher the number in the brand, the stronger and more reliable the product itself will be. For example, class A1 reinforcement is a smooth rod without ribs and with a thickness of up to 40 mm.

But reinforcement class A iii means that this material can withstand significant loads and interacts well with concrete as a stabilizing internal mesh.

Recently, a new labeling system has been increasingly used. It's a little different from before. The new valve marking consists of the letter A and a three-digit number. Here you should immediately notice that there is absolutely no difference in the products themselves. Only the markings differ.

For greater convenience, most manufacturers try to indicate in assortments the names of both marking systems.

For example, if you are interested in what class of A240 fittings, then just look at the appendix or at its full name. Surely it will be indicated there that this class of fittings, in terms of its characteristics, fully corresponds to products under the A1 brand.

There is another interesting feature of these materials. The letter C is often added to the name of the rods. It is added at the end of the name. Many people immediately have a natural question. For example, what class is the A500C reinforcement and how does it differ from similar rods, but with the name A500.

The answer to this question is very simple. This is still the same A500 class fittings, only with the possibility of its safe welding.

The fact is that when rolled, steel rods often lose their original structure. This has almost no effect on their basic characteristics, but the welds turn out to be very weak and fragile.

In capital construction, ignoring such things is completely unacceptable. Especially when you consider that most structures from reinforcing bars are assembled by welding.

Therefore, for materials that can be safely welded with any metal structures, the letter C is added to the marking. If the letter K is indicated, this indicates the increased resistance of the metal to corrosion.

Description and characteristics of each class

Before considering each class, you first need to understand what kind of rods there are in general.

These products are produced in two ways:

Using hot rolling, which makes it possible to directly produce rods for use in load-bearing structures;
Using cold drawing. This is how wire-type products are made.

According to the type of profile, the reinforcement is:

Smooth as adhesives for installation;
Corrugated.

Now let's look at the features of labeling and classification in more detail.

Class A 1 or A240 reinforcement is a rod with a smooth surface. It is drawn using cold manufacturing technologies. The thickness of the reinforcement is 6-40 mm. Models up to 12 mm in diameter can be knitted with special wires.

If the diameter is larger, then you will only be able to buy products in the form of rods. It is used for assembling small reinforced concrete structures with low tension. Reinforcement class A240 sells for $250-300 per ton.

Rods A2 or A300 already have a grooved profile. However, they have it about 2 times less frequently than standard models and are directed in the other direction.

The diameter of the rods is 10-60 mm. As in the previous case, products with a diameter of up to 12 mm can be sold and transported in coils. It can be bought for 350-450 dollars per ton.

Reinforcement class A3 or A400 is probably the most popular type of building materials. You can see it almost everywhere. And all thanks to excellent strength characteristics, optimal price and good adhesion with concrete mortar.

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With the help of such rods, almost all modern reinforced concrete structures are assembled and created, including frames for multi-story buildings, foundations, etc. Class A400 reinforcement is sold for $450-550 per ton.

The reinforcement class A500C or A500 can be classified as a separate class, although the characteristics of the rods in question almost completely replicate those of the A3 samples.

This reinforcement is made from alloy steel with a small proportion of impurities, which slightly increases its tensile strength and the quality of welded joints. The price of the products in question is also almost the same and equals 500-600 dollars per ton.

Classes A4, A5 and A6 are much less common. According to the new system, they are marked with the inscriptions A600, A800 and A1000, respectively. These rods are produced using hot rolled technology using a minimum amount of additives.

In appearance they resemble the A3 models, but have a rarer profile. Their possible diameter is 10-32 mm. The cost of these materials starts from $700 per ton.

Such samples are rare because they are quite expensive, and their narrow specialization and increased strength make them not very attractive for mass use.

Similar products are used in the construction of large factories and enterprises, where it is necessary to assemble truly stressed structures with serious length. It is produced exclusively in the form of rods.

There is also VR class fittings. This is a separate subtype of rolled metal, which is called nothing more than wire reinforcement. The thickness of such reinforcement starts from 1 mm and reaches 12 mm. It is drawn cold on special machines.

Using class VR samples, they are used to tie and tie monolithic structures, reinforcing mesh, etc. They sell wire reinforcement for 150-230 dollars 1 ton.

Production of corrugated fittings (video)

Source: http://HomeBuild2.ru/stroitelnye-materialy/klassy-armatury.html

Classification of fittings: types, classes and groups

03.12.2017

Difference between fittings A1 and A3. Characteristics and application in construction

Reinforcement is the basis of concrete walls, screeds and columns. This important element experiences all the main loads and bending moments, preventing deformation and destruction of the concrete base.

Metal rods of different diameters, which have a circular cross-section, are used as reinforcement. There are two main types of reinforcing metal rods: A1 and A3.

To understand the difference between A1 and A3 fittings, as well as their scope of application, it is necessary to familiarize yourself with their main characteristics and consider their advantages and disadvantages.

Explanation of markings

Marking of reinforcing bars is usually done using letter designations. The letters indicate the exact method by which the reinforcement was produced. So, for example, the presence of the letter A in the name indicates that the product was made using the hot or cold rolling method.

If we compare both methods, it is worth noting that the steel obtained by cold rolling has increased strength characteristics and has greater hardness. The number usually denotes the degree of fluidity of the steel used in the reinforcement; it determines the main difference between the grades of metal. The yield coefficient depends on the maximum stress, which causes the metal to begin to deform.

That is, the higher this indicator, the greater the strength of the rod itself. So, for example, A440 steel has a greater safety margin compared to A240.

When building structures made of reinforced concrete, it is necessary to achieve the best strength of the entire structure, using elements with minimal mass. One solution is to reinforce the structure using a steel frame, for the assembly of which reinforcement of various cross-sectional diameters is used. It can be in the form of skeins or rods.

Each type of reinforcement, regardless of its profile, can be subjected to separate temperature treatment. This can be understood by the addition of “At” at the end of the abbreviation. The reinforcement metal can be cleaned of excess impurities and have a uniform distribution of carbon, which increases the quality of welded joints (a “C” is added to the abbreviation). Copper can be added to the metal in an amount of up to two percent to improve its anti-corrosion properties (at the end of the abbreviation “K”).

Difference between fittings A1 and A3

The main types used in construction are A3, as well as A1 reinforcement, GOST 30136-94. Sometimes you can find other names. For example, A1 fittings are often found under the name A240, and A3 – A400.

The weight of reinforcement A1 and A3 is approximately the same, however, the main difference between these types of reinforcement is that A1 has a smooth surface, and A3 has a corrugated surface. Corrugation provides better contact with concrete. Due to the presence of a corrugated surface on A3, it has better reinforcing qualities compared to smooth reinforcement A1.

The disadvantages of A3 include the appearance of additional stresses due to the need for an additional rolling cycle, which is necessary to form a corrugated surface.

Another disadvantage is the reduction in the effective cross-section of the reinforcement with a constant weight per linear meter, as well as a higher cost due to the complexity of its production. Strength decreases by 6% with an asymmetrical position of the corrugation pattern compared to round reinforcement.

There are differences between reinforcement A1 and A3 in terms of the type of steel used. Typically, steel with a low carbon content in its composition is used for the manufacture of materials. For the manufacture of A3 reinforcement, steels with increased ductility and low carbon content are used. A1 reinforcement is made from stiffer and harder steels. Also, according to GOST, variety A1 should not have corrugation.

The cross-sectional diameter of the reinforcement bars, regardless of the profile, usually varies between 8-25 millimeters. When constructing larger structures, such as bridges and high-rise buildings, reinforcement with a diameter of 40 millimeters is used. The composition of the material with a smaller cross-section includes mild steel that is more deeply purified from impurities. For large diameter fittings, any type of steel with a low carbon content can be used.

Application of fittings

Let's talk about the difference between A1 and A3 fittings in terms of application. A1 is widely used for reinforcing concrete structures in any form, be it a mesh or a complex frame. Smooth reinforcement is also actively used in the construction of any structures that have an auxiliary value (fences, products in the form of gratings, fences, etc.).

A3 reinforcement, which is corrugated, is mainly used for the construction of simple, lightweight and high-strength frame structures made of concrete. This variety is not used in the construction of structures that perform an auxiliary function.

Source: https://FB.ru/article/353712/otlichie-armaturyi-aia-harakteristiki-i-primenenie-v-stroitelstve

What is the difference between A1 fittings and A240

The sale of smooth fittings requires markings A1 and A240. Many people wonder whether smooth reinforcing bars A1 (A-I) are different from A240, since the numbers are different.

Marking

In fact, there are no differences between these two types of markings. The reason for the unsettled name is that A1 is an old version of the marking, which many builders use and look for out of habit. A240 fully complies with smooth reinforcing bars in accordance with GOST 5781-82.

To avoid confusion in reference books and when working with old-school builders, very often companies indicate both names, despite the fact that one of them is outdated. In addition, it is much easier and faster to say and remember A1 than the number A240.

Application

The main feature of this type of steel reinforcement is that it is completely smooth. Consequently, it can be used for reinforcement as a reinforcing element with great difficulty, since the corrugated surface of the rods is needed for strengthening. But this reinforcement makes other elements well.

Firstly, it is widely used in production. Springs and other elements, bolts and rivets, fasteners and hardware are made from it.

Secondly, it is needed in some types of reinforcement, but rarely in reinforced concrete for foundations.

Thirdly, it is needed for pouring concrete, as welded lintels and additional elements in the reinforcement frame.

Finally, it can be used for decorative purposes as it looks good, is inexpensive and is easy to process.

Kinds

A240 (A1) is made from carbon or low-alloy steel. In the low-alloy version, manganese or chromium is most often added for strength.

If the marking contains the letter B, it means that this is reinforcement reinforced by drawing. And if the letter is T, then the product is made of steel that has already been heat-hardened.

The sizes range in rod diameter from 6 to 40 millimeters. The rods are 6-12 meters long, but if they are very thin (less than 10 millimeters), they are supplied not in the form of individual rods, but in coils or coils.

Source: https://sevzapstroi.ru/about-us/stati/chem-otlichaetsya-armatura-a1-ot-a240

A1 fittings and A3 fittings. What is the difference

There are many types of steel reinforcement. The most commonly used fittings are a3 and a1. The article talks about the differences between them, which material is more often used for certain jobs.

Characteristics of fittings

Profile type. It can be smooth or periodic, with longitudinal and transverse ribs. The ribbing improves adhesion to the concrete mortar, which increases the strength of the structure. Smooth reinforcement is much easier to weld.
Diameter of rods. The larger it is, the higher the strength. It must be remembered that along with the cross-section there is an increase in the mass of the reinforcement frame. In some situations this can be quite important.
Steel grade. The strength and anti-corrosion properties of the product depend on it. Corrosion resistance is important if the structure is located in an aggressive environment, places with sudden and large temperature changes and where there is high humidity.

In GOST 5781-82, for each grade and diameter, the characteristics of steel reinforcement are indicated, based on which calculations are made before construction.

Features of a1 fittings

Distinctive features and advantages:

The profile is smooth.
Made of low-alloy steel (St3sp, St3ps, St3kp).
The diameter of the reinforcing bars ranges from 6 to 40 mm.
Has high corrosion resistance.
Tolerates sudden changes in temperature and high humidity.
Easy to weld.

Flaws:

Poor adhesion to concrete mortar. However, for many jobs it is sufficient or does not play a significant role.

The old marking of the fittings is A1, the new one is A240. It is used for finishing facades, strengthening columns, for foundations and in reinforced concrete products (slabs, rings, beams, etc.).

Features of A3 fittings

Distinctive features and advantages:

Profile – with transverse or longitudinal ribs.
Steel grades - 35GS, 25G2S and 32G2Rps.
Diameter for rods made of steel 35GS, 25G2S from 6 to 40 mm.
Diameter for rods made of steel 32G2Rps from 6 to 22 mm.
Good adhesion to concrete and increased structural strength.

Flaws:

Low corrosion resistance.
High price compared to A1 fittings. A3 fittings are approximately 30% more expensive than A1.

The old marking is A3, the new one is A400.
It is used where increased strength is needed: in the construction of bridges, dams, in monolithic buildings where there are high loads and pressure. Often, fittings of both types are combined with each other.

Source: https://cxemok.ru/poleznoe/1666-armatura-a1-i-armatura-a3-chem-otlichayutsya.html

A240 fittings: Price, characteristics, use

A type of steel reinforcement A240. Price policy. Information about standards and features of the material.

Rolled metal products are presented on the market today in a fairly wide range, which undoubtedly makes the choice easier, allowing you to choose the best option for any production situation. Among all this diversity, steel reinforcement stands out, indispensable for a wide range of construction work, as well as relevant for other areas of human activity. One of its varieties, namely the A240 fittings, will be considered by us in this material.

Features and characteristics of fittings

The A240 fittings are an all-metal type profile, made of high-quality alloy steel with a low carbon content. This combination ensures fairly simple and durable welding of individual components to form a frame or structure of any complexity. The production process is regulated by GOST 5781-82, which also determines the range of materials.

The A240 marking indicates that this variation of fittings has class A1, which is distinguished by its reliability, strength, durability and unpretentiousness.

The product offers an exceptionally smooth profile, without any protrusions or grooves on the surface. Reinforcement of this type can be used both with and without prestressing.

Very often, A240 reinforcement is used on objects not prone to excessive loads, acting as an additional reinforcing element.

The following steel grades can be used as raw materials for the production of this fittings:

St3kp – structural boiling carbon steel of normal quality, the unique characteristics of which give the finished product additional flexibility;
St3ps – semi-quiet structural carbon of normal quality, suitable for welding and not prone to excessive fragility;
St3sp is a structural carbon calm material, which has increased strength and is used in the manufacture of products for arranging load-bearing structures.

The product is produced in full compliance with the current state standard, according to which its diameters can vary in the range of 6-40 mm, with a length of 6-12 m, which, depending on production needs, can be measured, unmeasured, and also unmeasured, but exclusively within measured limits.

The material can be presented on the market both in coils (product diameter no more than 10 mm) and in rods (product cross-section exceeds 10 mm).

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Material advantages

The A240 valve offers users the following benefits:

Reliability – a quality certificate allows the material to be used in the most complex and critical areas;
Corrosion resistance;
Immunity to chemical and biological influences;
Excellent flexibility indicators;
Hardness and strength;
Long period of safe use;
Availability and wide range.

Price policy

We are definitely pleased with the affordable price of the material, the average price of which per 1 ton of finished products for the central region of the country fluctuates within the following limits:

A240 8 mm – 26700 – 33800 rubles;
A240 14 mm – 24700 – 31500 rubles;
A240 16 mm – 24800 – 31500 rubles.

Conclusion

A240 fittings are a modern variation of rolled metal products, ideal for use in a wide variety of areas of human activity. The optimal combination of parameters, unpretentiousness and reasonable cost of the material allow it to rightfully occupy a leading position in the building materials market, leaving numerous competitors far behind.

Source: https://the-master.ru/armatura/armirovannaya-stal-a240

Assortment of fittings

Reinforcement is a steel product for strengthening concrete structures. It is used in the construction of foundations and load-bearing structures: lintels, floor slabs, columns, beams and arches.

The main standard regulating the production of the range of fittings is GOST 5781-81. Construction fittings of the A500C and B500C range are regulated by the updated GOST 52544-2006.

Reinforcement range – table

When calculating the permissible tensile load on a reinforced concrete structure, the diameter of the reinforcing rods is taken into account. In accordance with GOST 5781-81, there are 20 main diameters of reinforcement (the table below shows the weight in accordance with the diameter).

Diameter of fittings, mm	Cross-sectional area, cm2	Reinforcement weight, kg/m
3	0,071	0,055
4	0,126	0,098
5	0,196	0,154
6	0,283	0,222
7	0,385	0,302
8	0,503	0,395
9	0,636

Source: https://TreydMetall.ru/info/sortament-armatury

A240 fittings what class and some features of the brand

Rolled metal is presented on the market today in a fairly wide range, which undoubtedly makes the choice easier, allowing you to choose the best option for any production situation. Among all this diversity, steel reinforcement stands out, indispensable for a wide range of construction work, as well as relevant for other areas of human activity.

Reinforcement differs according to such criteria as the chemical composition of the material of manufacture (in this case steel), production method, main characteristics and cross-sectional diameter. The most popular among such metal products is A240 reinforcement with a diameter of 10 millimeters .

The main parameters by which a reinforcing element should be classified are:

Cross section type. The reinforcement product is produced in the form of a periodic profile with a flat or smooth surface.
According to production technology, cold-rolled and hot-rolled wire modifications are distinguished. They sell it in coils in the form of wire coils or rods.
Depending on the method of application in concrete, there are unstressed and prestressed reinforcement.
Strengthening method. Here there is reinforcement processed by hardening at high temperatures or tempering, or cold strengthening through drawing or stretching.

Features of fittings

Like all materials , this brand has some features that are important for its proper use:

Flexibility and rigidity.
Strength that remains unchanged despite any changes in the shape of rolled metal.
Due to special processing, it is capable of withstanding high mechanical loads.
Does not corrode.
Durability and strength.

All of the above points make it possible to use this reinforcement structure in a number of industries and areas, especially in the construction of multi-story and simply tall buildings.

It should be noted that there is a peculiarity in the marking of fittings of the specified brand. If the letter c appears, this indicates its weldability.

The reinforcement part of this brand is sold in various lengths, therefore, before working with floors and walls, it is necessary to cut the rods for the frame according to customer requirements. They are then held together by welding or wire.

The finished structure is installed in the required position, then filled with concrete mortar. As a result, everything freezes, and the reinforcement structure acquires the following advantages:

Reliability - a quality certificate allows the material to be used in the most complex and critical areas.
Corrosion resistance.
Immunity to chemical and biological influences.
Excellent flexibility.
Hardness and strength.
Long period of safe use.
Availability and wide range.

Thanks to its excellent performance parameters, A240 fittings can be used in the following areas:

Strengthening reinforced concrete structures.
Reinforcement of walls, ceilings and floors in buildings and structures of various purposes and types.
Production of building frames, meshes and various structures.
Production of various parts and mechanisms in mechanical engineering.
Creation of decorative metal products.

Where to buy

The reinforcement product is sold today in a number of specialized companies without restrictions in terms of standards and quantity. You can choose products of any size, length and performance characteristics, and also purchase the specified reinforcement structure in accordance with your financial needs and current situation.

You can also buy a reinforcement element with the specified markings in the online store, arrange for pickup or delivery. It is enough to call the construction company, consult with a specialist, clarify the time and terms of delivery, as well as the payment method (card or cash). Each store has a large selection of reinforcing elements for any customer.

However, it is very important to know the class of the chosen reinforcement structure and its characteristics, since the strength of the proposed structure, the cost of all rods and much more depend on this. You should choose based on the nomenclature, length and price per ton of material, as well as the wishes of the customer.

A240 fittings are a modern variation of rolled metal products, ideal for use in a wide variety of areas of human activity. The optimal combination of parameters , unpretentiousness and reasonable cost of the material allow it to rightfully occupy a leading position in the building materials market, leaving numerous competitors far behind.

Source: https://tokar.guru/metallicheskie-izdeliya/armatura/armatura-a240-kakoy-klass-i-ee-osobennosti.html

Difference between classes of reinforcement

Reinforcement is used not only for the construction and strengthening of walls from various materials, but also for creating screeds, bridges, dams or subways. Different types of rods are made from different types of steel and in different ways.

Types of fittings

Due to the raw materials used and the manufacturing method, reinforcing bars are divided into two main groups: assembly and working.

Assembly bars are used for the foundation of small buildings and for creating screeds. These are, most often, rods with a smooth surface and their diameter ranges from four to forty millimeters; they are not used for the construction of walls. They are classified as: class A1 (A240) fittings.
Working steel is used as the main support of the walls, so the rods are thicker, their diameter is from six to eighty millimeters, and they have a corrugated surface, because it is on them that the main load is placed. They are classified as: A2 (A300); A3 (A400, A500); A4 (A600); A5 (A800); A6 (A1000).

They can also be divided by surface type, since reinforcement is used in various conditions, for example:

Thermally strengthened, marked as T.
Weldable, marked as C, such rods are best suited for creating structures.
With an anti-corrosion coating, marked as K, such rods are not subject to rust.

Reinforcement can simultaneously possess several of these properties. Also, the steel used in the manufacture of rods can be:

Carbonaceous, with varying amounts of substance, the more, the stronger. Designated as St and with an index from zero to six.
Alloyed, with the addition of other metals.

Carbon steel (St) has varying degrees of deoxidation; it can be: calm - sp, semi-quiet - ps and boiling - kp.

The following are added to the alloy: carbon, manganese, silicon, nickel, chromium, copper, niobium, vanadium, vanadium nitrite, molybdenum, boron, titanium, aluminum, sulfur, phosphorus, arsenic, nitrogen and oxygen.

Class comparison table

Reinforcement class	Rod type	Rod diameter (mm)	Tensile strength (MPa)	Elongation at break (%)	Grade of steel used
A1 or A240	Smooth	From 6 to 40	373	25	St3kp, St3ps, St3sp.
A2 or A300	Fluted	From 10 to 40From 40 to 80	490	19	St5sp, St5ps, 18G2S.
A3 or A400	Fluted	From 6 to 22	590	14	35GS, 25G2S,
A3 or A500	Fluted	From 6 to 40	600	14	32G2Rps.
A4 or A600	Fluted	From 6 to 8 From 10 to 18 From 10 to 32 From 36 to 40	883	6	80С, 20ХГ2Ц.
A5 or A800	Fluted	From 6 to 8 From 10 to 32 From 36 to 40	1030	7	23ХГ2Ц.
A6 or A1000	Fluted	From 10 to 22	1030	7	22Х2Г2АУ.

Popular classes of reinforcement and their application

Reinforcement classes A1 and A2 are used to create reinforcing ties, since this type of rod is characterized by increased elasticity, but class A2 is more dense in structure.

Reinforcement class A3 (A400, A500) is considered the most popular, as it has a durable structure and inexpensive cost. Such rods are used in the construction of building walls.

Reinforcement class A4, most often used in the creation of reinforced concrete structures. Such rods are less easily welded, so they are usually tied up in frames.

Reinforcement classes A5 and A6 are the most expensive, but also the strongest, so they are used to strengthen and create large spans, for example, in the construction of factories or factories.

Comparative table of popular types of fittings

Properties of reinforcement	Class A1	Class A3
Flow marking	A240	A400, A500
Product type	Standard uncoated, welded.	Standard, Welded, Galvanized.
Steel composition	Low alloy steel grades St3kp, St3ps, St3sp.	High-alloy steel grade 25GS, 35G2S.
Rod surface	Smooth.	Corrugated.
Rod dimensions	Diameter from 4 mm. up to 40 mm., Length 11.7 meters.	Diameter from 6 mm. Up to 80 mm., Length up to 12 meters.
Application	Foundations of small buildings, Ceilings and beams, Screeds and columns, Arches and greenhouses.	For all types of buildings, Bridges and dams, Subways and piers, Road surfaces.

Visual comparison

The first class of reinforcement always has a smooth profile of the rod; very rarely it can be the second class, but all other classes have only a corrugated surface. Also, different classes differ in diameter, weight and length.

Reinforcement of the third and fourth classes are similar in characteristics, but the bars of the fourth class are larger, since higher quality steel is used in their creation. Reinforcement of the fifth and sixth classes is easier to recognize; the rods are much larger and longer, and they are also much more expensive.

This knowledge will help when choosing fittings, but you can simply contact a sales consultant.

Source: http://pkd-steel.by/poleznye-materialy/raznica-mezhdu-klassami-armatury

Main characteristics of A240 fittings:

A240 reinforcement is hot-rolled steel, which is an auxiliary element of structures and equipment and is widely used in construction and mechanical engineering. Any building material is divided into classes, and A240 reinforcement is the most popular of the rest.

Characteristics

The differences between A240 are its smooth profile and round cross-section, which implies insufficient adhesion to cement and allows this type of material to be used only as an auxiliary frame for buildings. According to GOST, there is no corrugation on the A240 fittings.

The rods are used in a tense and unstressed state.

A240 reinforcement is characterized by strength, rigidity, flexibility, and resistance to adverse external influences. Production is carried out in accordance with GOST 5781-82 from several types of steel.

Types of steel:

low-alloy carbon (with the addition of chromium, manganese): ordinary quality, for the manufacture of rods 2-12 m;
high quality alloy carbon: for rods 2-6 m;
highly alloyed - for rods 1-6 m.

Product compliance with GOST is verified experimentally. If compliance is not confirmed, then the use of the material is considered unsafe.

Distinctive properties in terms of chemical composition, production method, diameter, depending on the purpose of the A240 fittings include:

type of section (corrugated and smooth);
cold- and hot-rolled fittings;
method of application (tension and non-tension);
strengthening method: reinforcement processed by high-temperature hardening and cold method - drawing and stretching.

Based on the characteristics of the chemical composition of A240, it is suitable for aggressive environments; its interaction with chlorine and natural gas is acceptable (unlike A400 fittings).

Purpose

The main purpose of the presented material, namely A240 fittings, first class:

production of parts to impart strength to metal products;
as components of mechanisms;
auxiliary reinforcement of walls and floors in multi-storey buildings;
production of fasteners (bolts, rivets);
for creating structures (fences, gazebos, borders, gratings, nets, stairs);
fixation of reinforced concrete products for transportation.

Markings:

AZK is an abbreviation for the characteristics of a rod with additional corrosion protection;
K - means treatment with a protective protective compound;
C - marking of the material intended for welding (not every class of reinforcement connects well enough to another).

Purchasing Guide

Typically, reinforcement is sold based on its actual weight. When calculating weight and cost using tables, it is necessary to take into account the possible discrepancy of values by 3-5% in either direction.
Smooth profile - usually always first class, less often - second. The third class and higher are produced corrugated.
Classes A3 and A4 have a similar diameter, but A4 has a higher quality composition.
Differences A5 and A6 - they belong to enlarged steel-rolling products, have a large length, a ring-shaped or crescent-shaped profile.

Keeping in mind these simple features of reinforcement classes, you can do without studying the documentation when ordering material.

Storage and transportation

The supplier must act in accordance with the delivery rules: products with a cross-section of up to 10 mm are transported in coils weighing up to 1.5 tons; with a cross section of more than 10 mm - tied around with wire. Each coil is marked in accordance with the regulations. Products with a diameter of up to 12 mm are transported in coils and separate rods, and with a cross-sectional diameter over 12 mm - only in rods.

Reinforcement is packaged in bundles weighing up to 15 tons, but at the customer’s request, packing bundles of 3-5 tons is acceptable. Products must be stored exclusively in closed warehouses. The rods are placed on a stand about 2 m high.

A240 fittings are supplied, as a rule, without significant defects inherent in other classes, including subtle rust and local contamination.

The increased demand for the material is due to the relatively low cost of this type of fittings.

Source: https://www.syl.ru/article/322366/osnovnyie-harakteristiki-armaturyi-a