Channel bars 20, due to their design, wall and foot thickness, are used in the construction of massive high-rise buildings, industrial facilities. They are made of hot rolled steel according to GOST 8240-97. Shelves are located on one side of the wall. In contrast to the zeta core structures, standard sizes and weights are produced, and deviations are allowed within 5%. Given that such channels can have a different angle of inclination of the walls, it is recommended that you familiarize yourself with the technical characteristics and scope of metal structures before buying.
What steels are made of channel 20?
Based on GOST 8240-97, channels of grade 20 are made of hot and cold rolled steel. The type of steel used in the manufacture of the channel is indicated in the marking. The hot-rolled channel is more durable, it is used in the construction of load-bearing walls in metal structures. They cope well with local vertical bending, resistant to horizontal movements. Cold-rolled channel 20 is more used for floors, where detailed calculations of the bearing capacities of buildings are not carried out.
Sizes and characteristics of channel marks of brand 20
Channel 20 (weight 1 meter 18.95 kg) is produced in two versions:
- Type U. It has a slope of the internal faces, the angle is 4-10 degrees.
- Type P. Channel with parallel walls.
Typical sizes of U20 channels:
- 200 mm - wall width;
- standard shelf width up to 76 mm;
- the walls have a thickness of 5.2 mm and a shelf thickness of up to 9 mm with fluctuations of up to 0.5%;
- turning radius at the junction of the inner edge of the shelf and the walls - 9.5 mm;
- About 54.43 m of channel will be in a ton of finished products.
Channel bars of a series P
Many sizes and parameters fully correspond to the U20 brand channel, only the radius of the outer rounding of the shelf is up to 5.5 mm, the inner turn is up to 9 mm. The mass of the channel is slightly less, so there are more structures in a ton of finished products.
The mass of the channel is calculated in accordance with the type of steel used at a density of 7850 kg / m 3 . This is a reference value. This parameter also depends on the composition, because the wall thickness can vary within 1%.
Parameters of channel length for private delivery
At production facilities, all channels are produced in the form of a single strip, which is cut on machines to a length of 2-12 meters. The length depends on a number of conditions, some are set by manufacturers, others by metal depots:
- Measured length. It is 1.1-2.0 meters.
- The combination of measured and unmeasured length with the composition of unmeasured lot in the supply group up to 5%.
- Multiple measured length.
- Only unmeasured length - 1.1 meters.
- Under the individual order of the buyer.
The channel is being packaged in a batch of 4.5-8 tons, tightened with steel tape in several places. At the ends of the batch, marking tags are installed, on which the brand of the channel, sizes and type are indicated. The transportation method is automobile and railway transport.
Scope of application
Channel marks of brand 20 are used in the construction of load-bearing metal structures of industrial and residential buildings, as well as for the construction of farms, arched ceilings. The products are suitable for the construction of pile-grillage foundations and as supports for small automobile bridges. When buying products, it is recommended to make a minimum of welding joints, it is better to initially install ready-made monolithic structures without intermediate joints. If necessary, welding is allowed in the places of installation of vertical supports and struts.
Channel 20 reviews received the most positive. Builders noted a sufficiently high strength, reliability and economy of this material, as well as ease of installation, excellent weldability, which speeds up and facilitates the construction process.