The channel is one of the most popular types of metal products. This kind of metal rolling is distinguished by its durability, wide assortment and affordability, which is why it has found application in many areas of construction and industry.
Definition and assortment
The channel is a metal product, the profile of which is in the form of the letter P. The horizontal jumper of this letter is called the wall, and the sides forming the legs of the letter P are called shelves.
Companies involved in the production of these products offer a wide range of products that differ in a number of characteristics:
- material of manufacture;
- mode of production;
- dimensions (this concept includes wall thickness, shelf width and height).
These indicators directly affect the cost of metal products and their operational features.
What to look for when buying?
In relation to the channel (as well as other sections of the beam), there is one general condition for selection. The basis is a specific engineering task. In the case when the parameters of the channel are inferior to the nearest standard version by less than 5%, then it is worth choosing this product number. If the discrepancy in the parameters is more than 5%, then this number is discarded in favor of the following.
What are channels made of?
In the market of goods you can find 2 types of channel:
- from aluminum alloy;
- of steel.
Steel channel has become much more widespread among consumers, as it differs in affordable price and high rates of strength and durability. In turn, steel products also differ in the type of steel used. It:
- channel from carbon steels - the quality of such products is regulated by GOST 380-2005;
- channel from low-alloy steel grades - in this case, quality control is carried out on the basis of GOST 19281-89.
Features and specifications
The active use of steel channel in the construction and manufacturing sector is due to several advantages. The fact is that this particular type of metal products surpasses other types of metal rolling in some respects.
- High rigidity. The channel bar has one of the highest rates of deflection strength (rigidity). This is explained by the structural features of the product - the separation of the metal from the axis of inertia is the maximum possible. Only an I-beam has a higher indicator , however, compared with a channel, it is much more difficult to produce, which ultimately affects the cost of production.
- Universality. Thanks to the U-shaped profile, the steel channel channel is convenient to use in production. It is easy to weld another part to it to create one or another design. The same I-tee loses noticeably in this respect. This allows us to find application for the U-shaped profile not only in construction, but also in mechanical engineering, the production of special equipment and many other areas of activity.
- Large assortment of steel channel. Manufacturers offer many different types of this type of metal products, so for any purpose you can choose the most optimal version of the product both in cost and technical characteristics.
Channel hot-rolled
In production, 2 types of technologies are used, in connection with which the channel is usually divided according to the type of manufacture into 2 main types:
- hot-rolled (an assortment of a steel channel of this type is used infrequently);
- cold-deformed, or otherwise bent.
Hot-rolled technology provides for the production of high-quality rolled metal from special billets that are rolled on special machines. The dimensional accuracy of such products is different:
- A - such marking corresponds to a channel with high accuracy of dimensional parameters;
- B - dimensional parameters of increased accuracy;
- In - the usual indicators.
Products with rolling precision A and B belong to the highest quality metal products, therefore the cost of such a channel will be an order of magnitude higher.
Regulates the quality of the hot-rolled steel channel GOST 8240-97.
Channel bent
The bent channel is a metal with a U-shaped section made by the technology of cold deformation. This technology is significantly different from hot rolled. For this, sheet steel is used as feedstock, which is cut into strips, and then rolled on special bending machines. This happens at ordinary temperature by pressing and running.
There are several differences between a bent steel channel.
- Visually, this type of metal can be recognized by the rounding of the outer corners.
- No product defects. This characteristic is due to the timely correction of defects during rolling on the machines. It is this feature that can be considered an undoubted advantage, since then you will not have to correct defects.
- The prices of a bent product are an order of magnitude lower, since production requires less cost.
Fields of application
To choose the best option for the product, you should consider their features. Hot-rolled steel channel has increased resistance to lateral and axial deformations. This is what makes it indispensable in the construction of bridges, industrial buildings and other facilities that experience increased loads.
The bent channel is slightly inferior to the hot-rolled channel in terms of strength, so it is used if there are no increased requirements for the object. When you can safely choose a bent type of product:
- as additional reinforcing elements in the construction of frames;
- during the reconstruction of residential and industrial construction projects - such a move allows you to reduce the load on the building foundation;
- in automotive industry and carriage building;
- during finishing works (installation of partitions in residential, industrial and commercial buildings) - in this case, it will be possible to build strong reliable partitions without heavy load.
Product series
To choose a metal product that exactly meets the requirements, it is worth considering the existence of various series. They differ in the presence or absence of a slope of the shelves and the size of the profile.
According to GOST, the steel channel is presented in several separate series, which are indicated in capital letters:
- P - shelves of such a product have a parallel arrangement (classic and most common version);
- L - lightweight (light) series, where the shelves are located in parallel (in such products, the shelves and the wall are thinner than usual);
- E - an economical series with parallel faces (in this case, the shelves have a smaller thickness, and the shelf is normal);
- U - channel, the edges of the shelves of which are able to slope (no more than 10%);
- C - products for special purposes.
Channel dimensions
During production, several parameters are taken into account. This is the total length of the product, the height of the channel (an indicator between the external sides of the product), the thickness of the shelves and partitions.
The height can vary between 50-400 mm, and the width of the shelf does not exceed 32-115 mm.
The length of the produced channel can be different. Depending on this indicator, a measured and unmeasured channel are distinguished. According to GOST, the range of steel channels can have a measured length of 4-12 meters (most often it is 12). However, sometimes you can find products with a length of 11.7 meters. Unmeasured length can be at least 3 and not more than 12 meters. When buying a batch of rolled metal, it can contain not only a measured, but also an unmeasured channel, but its quantity should not exceed 5% of the total purchased volume of products.
Galvanized products
Among a wide variety of rolled metal products, galvanized products occupy a special place. Their hallmark is the presence of zinc coating. This layer is applied to the surface during the manufacture of products and plays a mainly protective role.
Zinc coating protects the metal structure from moisture and prevents the formation of corrosion. Thanks to this, it is possible to significantly increase the strength of the object and its service life. It is recommended to choose a channel with a zinc coating in those cases when the object is constantly exposed to moisture.
When buying metal, you should be extremely careful about the choice of supplier and the quality of the products purchased. Each batch must be accompanied by quality certificates for compliance with GOST. In addition, it is important to verify that the product does not have visual defects, as this will directly affect the quality and durability of the finished structure.