Channel dimensions according to GOST: hot-rolled, bent

To make a strong frame, a profile pipe is often used. But this is not the only option. There is also a channel. Due to the presence of stiffeners at the bends, it has a high bearing capacity, lower weight and cost. And the dimensions of the channel according to GOST allow it to be used even to create loaded structures.

What is a channel and its types

A channel is called a U-shaped shaped metal product, which is made of black and alloy steel. The main property is high resistance to vertical bending loads. It is lower than that of I-beams, but the price of the channel is not so expensive, and the mass is less.

By the way, the “legs” of the letter “P” are called the shelves of the channel, and the jumper between them is called the back. And the channel number (the number that comes after the symbol) reflects its height (the width of the back).

Use a channel when creating frames to increase the bearing capacity. For example, when constructing ceilings, above door and window openings, when constructing stairs, and railings to them. This is what concerns private construction. In general, the channel is used in the construction of wagons, cars and ships. Bridges and cranes are assembled from them. In general, the scope is wide.

Standardized Views

According to the manufacturing method, the channels are hot-rolled and bent. Bent can be with shelves of equal or different lengths. They differ from rolled ones by a smoother rounding at the transition points of the back to the shelves.

Rolled can be with parallel shelves – series P or with a slope of shelves – series U. But you should not think that “slope” is the slope of the shelves. They, in any case, should be perpendicular to the back. A slope is understood as a smooth and gradual decrease in the thickness of the shelves. It can be from 4% to 10%. There are three more types of rolled channels. They differ in the length of the shelves and their thickness: C – special, L – light and E – economical.

Bent channels, by the way, have their own designation. They have two of the same classes. One has shelves of the same length and is called equal-shelf, the second has shelves of different lengths, they call it different-shelf.

Also, in the specification or marking of channels, an accuracy class is affixed: A – high, B – normal. Bent ones also have class B – this is increased accuracy. High and increased accuracy is usually required for industrial applications. For private construction, class B is more than enough.

Expansion of the range

Standard channels are made for connection by welding. But there are designs that are more convenient if it is possible to assemble and disassemble them. For this, perforated U-shaped rolled metal products are produced. It is made of galvanized sheet steel with a thickness of 2-5 mm.

The perforated channel SHP is indicated, then the number of perforated edges is indicated, and then the dimensions in millimeters. The first is the height of the product (the length of the back), and then the length of the shelves. ShP size range – height from 50 mm to 400 mm, shelf length – 20-180 mm. Shelves, racks, other storage systems, scaffolding are assembled from perforated rolled products.

There are several special series of perforated channels. K235, K225, K240 – wiring with perforation. They are used to create systems in which cables are laid. Metal conducts heat well, and the presence of holes further increases this figure.

There are also aluminum channels and aluminum alloys. They are not used in load-bearing structures. Often used as a finishing or decorative element. May be part of separation systems. For example, office partitions, racks, tables, consoles, etc. Small-sized aluminum channels can be used to install LED backlighting, since aluminum removes heat very well, and this is a guarantee of the durability of LEDs.

Standards

There are nine standards that prescribe different types and types of channels. They list the entire assortment, specifications and designations. But most of them are special types and types that are made by order of enterprises. They do not go on sale, and they are not needed at a regular construction site or on the farm. For example, GOST 21026-75 describes specific channels for the mining industry. They feature curved shelves. Standards 5267 describe varieties for the railcar industry.

The parameters of channels of “wide use” are prescribed in three standards.

• GOST 8240-97 (instead of the old 8240-89). It lists the range and dimensions of hot-rolled.
• The dimensions and parameters of the bent ones are prescribed:
  • GOST 8278 – with shelves equal in length
  • GOST 8281 – with shelves of different lengths.

These documents describe the dimensions of the channel according to GOST, weight, technical parameters and tolerances. Please note that the bearing capacity is not written, as it strongly depends on how the channel is laid. The maximum load is calculated for each specific case, so there are no tables with such data.

Assortment of hot-rolled channels according to GOST 8240-97

The main area of ​​application of a rolled channel is the creation and strengthening of load-bearing structures. Therefore, it is necessary to strictly adhere to the parameters. The standards describe all values, up to tolerances. Usually they make up no more than a few percent of the parameter, but there are exceptions.

Also note that the weight of the channel is given for reference. That is, it is designed for steel of a certain grade. In the standards, its density is 7,85 g / cm³. For denser steel, the weight will be more, for more porous, less. The exact weight must be specified by the manufacturer, as well as the steel grade and its density. Channels are made from 2 to 12 meters long, there may be longer ones.

There are also roundings and slopes of the shelves in GOSTs, but they are given for building a profile, and not for control. Consumers don’t need this information, so we didn’t include it in our tables.

There is no special marking. The height of the product is simply indicated in centimeters, followed by a letter that indicates the type of section and group. For example, channel 6,5E (back height 6,5 cm, economy group, and the remaining dimensions of the channel according to GOST, see the table), 12P or 12U – these products have a height of 12 cm, but one has parallel shelves (which is 12P), the other with a slope (12U). In addition to these numbers, an accuracy class can also be indicated. There are no other parameters – the length of the shelves, the thickness of the back and shelves – in the designation. Therefore, tables with dimensions are needed for this type of metal products. Below they are listed by class.

Dimensions and weight of rolled channels

Channel U differs in that its shelves from the back to the ends are getting thinner. This gradual decrease in thickness is called slope. If you look closely at the U and P profile drawings, you will see the difference.

The height of the rolled channels U is from 50 mm to 400 mm, the width of the shelves is from 32 mm to 115 mm. Standard gauge and weight are listed in the table.

Special rolled channels C: dimensions and weight of one meter

On the basis of a range with a slope, special channels are produced. They have one or more different parameters. In some cases, the length of the shelf is increased, in others the difference is in thickness. In general, if you need a channel with a slope, but you did not find suitable dimensions in the U series, see also the C series.

The most popular sizes are those that differ significantly from the standard. For example, the 18Sb channel has shelves 100 mm long, while the standard version – 18U is only 70 mm. Both the back and the shelves are thicker: 8 mm and 10,5 mm versus 5,1 mm and 8,7 mm in the base series. As you can see, the difference is significant. The channel 18Sb is more powerful than the basic version – 18U.

Parallel Flanged Channel Dimension Table (No Slope) P Series

Channel P has the same thickness of the shelves along the entire length. Only towards the end they are smoothly rounded. The radius of curvature is not controlled, as it is of no fundamental importance.

If you compare the two tables, you will see that the dimensions of the channel according to GOST U and P of the type of the same height are no different. All parameters are the same. Everything. Even the weight of one meter. The difference is in the shape of the shelves. Moreover, private traders often choose parallel shelves. Any material fits tightly on even shelves, there are no problems with the connection.

Assortment of rolled channels of group E (economy) with dimensions and weight

Channels with straight shelves are also of the E series – economy. They differ from the P series in a slightly smaller back thickness. The rest of the parameters, except for the weight, are unchanged. Weight, of course, is slightly less.

It is worth saying that a decrease in the thickness of the back does not have a significant effect on the bearing capacity. But the mass is decreasing. So this is really an economical channel. Both in terms of metal and in terms of price. Less material consumption means less cost. If there is a need to save money, you can buy a channel E.

Light channel (L series)

Lightweight channel L is useful in those structures where the load is not so great. It also has parallel shelves, but they are shorter and thinner. Thinner and back. And this means that the lightweight series has less weight and, as a result, a lower load-bearing capacity. But large loads in the private sector are not so common, so the L channel for private construction is even more suitable. But the bearing capacity is better to calculate.

Let’s compare the channel 14L and 14P for example.

• 14L has the following dimensions of shelves: length 32 mm and thickness 5,6 mm. Back thickness 3,2 mm.
• 14P dimensions: with a shelf length of 58 mm and a thickness of 8,1 mm, a back thickness of 4,9 mm.

The difference is more than significant. It is also reflected in weight: a 14P meter weighs 12,3 kg, and a 14L running meter weighs 5,94 kg. Twice smaller. This affects the cost of rental (of course), the cost of delivery. In addition, it is lighter, it is easier to carry, lift, etc. But 3,2 mm is closer to thin metal. This means that you must be able to weld thin metal.

Channel dimensions according to GOST bent type

The channel is called bent because the sheet of metal is bent on bending machines. It is not possible to get a clear angle, as on hot-rolled ones, and the rounding at the transition point of the back to the shelf is smooth. It is in this part that one species can be distinguished from another. This option is good because it has a lower price. This is due to a simpler production technology.

As already mentioned, the shelves of a bent channel can be the same or different lengths. More assortment of the same. It makes no sense to give tables of dimensions for a bent channel. All the required parameters are written in its marking. For example, 100*50*2. Everything is simple here: the first is the height, the second is the size of the shelves, the third number is the thickness of the metal. It is not much more difficult with different-shelf ones: 65 * 55,20 * 3,5. This is a channel with different shelves. The first number is the height, the second is the length of the long shelf, the third – separated by a comma – is the short shelf, and then the thickness of the metal.

Dimensions with the same shelves “from” and “to”

To choose a material for your own needs, it is advisable to know the minimum and maximum size of this type of rental. Of course, the dimensions increase with some step, but you can roughly orient yourself, and then see what they offer you at the local metal depot.

The run-up of the parameters of a bent channel with the same flanges depends on the type of steel from which the product is made. The dimensions of the channel according to GOST can be as follows:

• Carbon steel boiling and semi-calm:
  • height 25-410 mm,
  • shelf length 26-180 mm,
  • thickness 2,0 – 8,0 mm.
• Carbon steel, calm and low-alloyed:
  • height 25-310 mm,
  • shelf length 26-160 mm,
  • thickness 2,0 – 8,0 mm.

Note. Unlike rolled, bent has the same thickness both on the back and on the shelves. It is understandable. Just a strip of metal bent. In a katana, the workpiece is heated, and then the necessary parameters are formed. And this is the fundamental difference.

It is also desirable to know how one type of steel differs from another. Everything is clear with alloyed compositions, the properties of stainless steel are known to everyone. And what is the difference between carbonaceous – boiling, semi-calm, calm? And the fact that the calm one welds well, the boiling one is the most difficult for welding, the semi-calm one in this parameter is somewhere in the middle.

Dimensions of a different shelf

As for the multi-shelf version, it is also made from the same steel grades. But the range of parameters does not depend on the type of material. Not in the sense that all sizes are the same, but in the fact that their limit values ​​- the largest and smallest – are the same. And the dimensions – the height and length of the shelves – of course, are different.

So, the dimensions of a bent U-shaped channel with different shelves can be as follows:

• height 32 – 300 mm;
• shelf length:
  • long 22 – 160 mm,
  • short 12 – 90 mm,
• channel thickness 2,0 – 8,0 mm.

As already mentioned, when designating the dimensions of this rolled product, the length of the shelves is indicated through a comma. The first digit is a long shelf, the second is a short one. For example, 90*80,50*4. We read like this, a bent channel 90 mm high, a long shelf 80 mm, a short one – 50 mm, a metal thickness – 4 mm.

Designation on the drawings

There is no special graphic icon to designate the channel. In the drawings, any rental is indicated simply by a line. Nearby there may be a letter designation or part of it, which is important specifically for this section or node. In the example below, the letters ШБ are used, which means that class B is required for rolled metal. Specific material grades are indicated in the specification. GOST and size are prescribed there. For example, GOST 8240-97, channel 12P. This means that a rolled backrest height of 120 mm and parallel shelves is used.

In other cases, when some complex nodes are displayed in detail on the drawings, the sectional channel is designated exactly as it looks: with the letter “P”. Unfold it the way it should be laid.

Specific dimensions are specified in the specification. Everything is clearly stated. A similar form of writing denotes a rolled type. For bent, the parameters of the shelves would be indicated. For example, it would stand there: 80 * 60 * 4,0 or some other numbers from tables with standard sizes.