Valve A3: price. Fittings A3: GOST

A3 reinforcement is a special hot-rolled steel of circular cross-section with a periodic profile intended for better adhesion to concrete. Such a rod is manufactured in compliance with the standards prescribed in GOST T5781-82.

general description

The main distinguishing feature of the A3 armature is that on its surface there are two longitudinal ribs, between which there are corrugations in the form of a "Christmas tree" (on the one hand the left screw, on the other - the right one). There is also a special purpose rod A3. The corrugations in this variant can go in one direction.

Diameter A3 can have different (6-40 mm). Thin rods (up to 10 mm) are supplied both in the form of cut rods and in coils. Thick products - only in rods. The length of the latter in both cases can be 6-12 m.

What is produced from

The valve A3 can be made of steel:

• Carbon of usual quality (st.3ps, st.3sp);

• Low-alloyed (35GS, 25G2S).

Steel grade 35GS has a short-term strength of 590 MPa, an elongation at break of 14% and a yield strength of 390 MPa. For the material 25G2S, these characteristics are the same in accordance with GOST 5781-82 and are equal to 980 MPa, 7% and 785MPa, respectively, according to GOST 10884-71. The steel used for the manufacture of A3 fittings can include elements such as boron, manganese and magnesium.

Scope of use

The field of application of reinforcement A3 is quite wide. Use this rod:

• When building bridges and other loaded structures;

• Laying of road surfaces;

• Construction of underground engineering systems, tunnels for trains, subway, metro;

• Devices of various kinds of metal structures in moist soil;

• In the construction of civil and military installations in areas with a harsh climate.

Cost of material

Of course, the first thing that they pay attention to when buying rods is their price. Armature A3 in general is not too expensive. The price for it depends mainly on two factors: the diameter and the manufacturer. Wholesale suppliers usually indicate the cost of this material in tons. The price for the A3 armature, sold at retail, is determined for one running meter. Below we present to your attention a table with the prices for the most common variants of such a rod.

What is the value of the valve A3

Above are given approximate quotations for a rod A3 from carbon steel. In some cases, its cost may be different. The price of reinforcement A3 depends mainly on the following factors:

• Stamps used for the manufacture of steel. Fittings made of low-alloy steel are worth more than products from st.3ps and st.3sp. But at the same time it is characterized by better performance characteristics.

• The diameter of the reinforcement. With the decrease of this indicator, the price for A3 rods increases. At the same time, the most demanded diameters (for example, 12 mm) may from time to time be deficit. In this case, the price of the bar, of course, rises.

• Season of sale. The most expensive A3 fittings are in the spring - in April-May, that is, when the construction season begins. The maximum discount for this product can be obtained in December.

• The amount of purchase. When ordering a very large wholesale lot of the company, manufacturers and suppliers can make a good discount to the buyer. At retail, the armature, of course, costs a little more.

• Places of purchase. At dealers, a ton of reinforcement will, of course, cost a little more than directly from the manufacturer.

Measuring fittings (with adjustable length parameters) are more expensive than immeasurable.

What to look for when buying

Consumers of this product are looking for it primarily on labeling. For example, someone needs 12 A3 armature. This means that a person wishes to purchase a variant of A3 rod with a diameter of 12 mm. Products manufactured with exact compliance with all GOST standards and labeled according to certain rules. The first place is the diameter of the realized rod in millimeters. Next is the specification of the actual product class (in our case A3). Then the number of reinforcement in the international classification (A400 for carbon steel or A500 for low-alloyed) is affixed. And in the last turn the GOST is indicated, according to which the armature (5781-82) was made.

For example, the same rod with a diameter of 12 mm made of low-alloy steel will be marked as follows: 12-A-III (A500) GOST5781-82. According to the regulations, no additional letters and numbers should be included in the marking of A3 fittings.

What you should know about

The final price of the reinforcement purchased sometimes also depends on the value of the additional services rendered by the supplier. It can be, for example:

• Cutting of the reinforcement supplied in coils to rods of the correct size;

• Delivery of purchased products.

As a rule, large quantities of sold reinforcement can be sent to any regions of the country. Small-scale sellers carry out delivery on this particular city or region.

When buying a material, among other things, you should ask the seller for a certificate. The valve A3 must have characteristics that exactly meet the requirements of GOST.

Operational characteristics

The popularity of A3 fittings from builders is primarily due to the fact that its use allows the construction of the most durable and durable reinforced concrete structures. In addition to the A3 rod, the modern industry produces option A1. Such an armature is not corrugated. And consequently, the degree of its adhesion to concrete is lower. Armature А3 and А1 is most often used for the erection of various types of reinforced concrete structures. In this case, the variant A1 is usually used in the construction of various auxiliary elements, and A3 - loaded. For example, it is the latter option that should be used when pouring the foundations of buildings. In addition to the high degree of adhesion to concrete, the A3 valve also has some other advantages.

1. Since the crescent and transverse ribs of such rods do not intersect, the material at high strength also differs in plasticity.

2. The valves A3, whose characteristics are simply excellent, can be used practically under any conditions. This rod does not lose its strength even at a temperature of -55 degrees.

3. The variant of A3 rod made of carbon steel is easily welded. Under certain circumstances, A3 bars from low-alloy steel can be joined in this way.

Norms of GOST

In the manufacture of A3 fittings, the following GOST requirements must be observed:

• The curvature of the rods should not exceed 0.6% of the measured length.

• On the surface of the ribs of the bars there should be no cracks, rolling captures or sunsets.

• Carbon steel, which complies with GOST 380 standards, must be used for the rod production. The required characteristics of low-alloy steel are determined by special tables.

For bar steel A400 25G2S, the temporary resistance index can be reduced to 560 MPa.

Packing of rods according to GOST

The order of this procedure is also regulated by GOST. Armature A3 is packed in compliance with the following standards:

• The mass of bundles of reinforcement bars should not exceed 15 tons;

• Fasten the ligaments only with wire or wire;

• At the customer's request, the rods can be packed in bundles of 3 tons or 5 tons;

• On each bundle a label with class A3 should be hanged.

Transport rules

The A3 armature can be transported both by road and rail. When carrying out loading and unloading operations, it is necessary to ensure that the products are not deformed or destroyed for any reason.

Store A3 valves in warehouses with normal or low humidity. It is prohibited to store it directly to the ground by regulations. The rebar must be stored in bundles on wooden pallets or shelves. When stacking, make sure that no parts of the material are sagged.