A metal corner is a product widely used in industry, in the construction of buildings and structures, as well as in other areas of the national economy. Due to the special design, this type of rolled products has increased rigidity and can be used to assemble frames with a large margin of safety. It is a corner of a long steel product in cross section resembling the letter "G". There are only two of its main types: equal and unequal. In the first case, the width of the "shelves" of the products is the same, in the second - different. The dimensions of the metal corner, its weight and the type of material used to manufacture the material are regulated by GOST.
Classification
Equal and unequal corners can be:
The first variety is characterized by increased strength. Such a corner is usually used in the construction of metal structures subjected to increased loads. Bent corners are the most popular. They are used everywhere. They are made by bending steel strips on special pressing equipment.
Also, these metal products are classified into:
The first variety is marked with the letter "B", the second - "A".
Metal angle length
According to this parameter, products are classified into dimensional and non-dimensional. There is also a corner of multiple lengths and limited. Measured products can have a length of 6, 7, 9, 10, 11 or 12 m. Their cost depends on the weight (i.e., the consumer pays not for the unit of the product, but for the total weight of the purchase, or, in extreme cases, for the meter). An unmeasured corner can have any length. In this case, this indicator varies from 4 to 12 m. Most often, building materials of this type are not too long, since they often are simply trimming of measured products.
Sometimes in the manufacture of various kinds of frames, load-bearing structures, etc., it is required that the dimensions of the metal corner be non-standard. In this case, the consumer has the opportunity to order products longer than 12 m.
Length errors
In addition to everything else, GOST also regulates the maximum deviations of the corner according to this parameter. The latter should not be more than:
30 mm for a corner 4 m long;
40 mm for products up to 6 m;
70 mm for a corner from 6 to 12 m long.
At the request of the customer, these parameters can be changed in the direction of greater accuracy (40 mm for products 4-7 m plus 5 mm for each meter of length over 7 m). GOSTs regulate not only the dimensions of the corner of a metal of equal equal and unequal, their weight and maximum deviations, but also the degree of their curvature. After all, quality products must be even. The maximum value of the angle curvature according to GOST should not exceed 0.4% of the length. At the request of the customer, enterprises engaged in the production of rolled metal products are manufactured with a curvature of not more than 0.2% of the length. Twisting the corner in the direction around the axis of GOST does not allow.
Shelf Width and Weight
What, in fact, can a corner have a metal size? GOST primarily regulates the ratio of the width of the shelves of these products, their thickness and weight. The first indicator varies from 20 to 200 mm. The thickness of the products can reach 16 mm. What exactly should be the ratio of the width of the shelves and the weight of 1 linear meter of the product, see the table below.
Shelf Width (mm) | The thickness of the steel used for the manufacture (mm) | Weight (kg) |
thirty | 3-4 | 1.36-1.78 |
35 | 3, 4 or 5 | 1.6, 2.1 or 2.58 |
40 | 3-5 | 1.85, 2.42, 2.98 |
fifty | 3, 4, 5, 6 | 2.32, 3.05, 3.77 |
70 | 4.5, 5, 6, 7, 8 | 4.87, 5.38, 6.39, 7.39, 8.37 |
The ratios of values ββfor equal-shelf products are presented above. As you can see, with the same width of the shelves, their thickness can be different. Accordingly, the weight of the product also changes. The dimensions of the corner of the metal unequal, or rather, the width of its "shelves", can also vary between 20-200 mm. The ratio of this parameter and the weight of the products in this case is regulated by GOST and is indicated in special tables.
Steel grades
The strength of the metal corner depends not only on the method of its manufacture, the thickness and width of the shelves. It also influences this parameter and which material was used to manufacture the product. They make a corner from the following types of steel:
carbon of usual quality;
low alloy high strength.
In the first case, metal grades are used, the operational characteristics of which are regulated by GOST 380-88. The quality of low-alloy steels used for the production of angle is determined by GOST 19281-89.
The most popular sizes of metal corner
The most demanded products of this type are products bent from ferrous metal of brand βBβ. This option costs less than a Class A stainless steel bracket. At the same time, such corners have a sufficient margin of safety so that durable and reliable structures can be assembled from them.
What are the most popular sizes of a metal corner? 40 x 40 mm, 50 x 50, 70 x 70 and 100 x 100 mm - this is the most popular shelf width. The first version of the products, for example, can be used for the manufacture of canopies, gazebos, benches, street tables, etc. For not too critical structures, such a corner has a sufficient margin of safety.
Products 50 x 50 mm can be used in the assembly of fences, gates, gratings, small children's swings, etc. They use this material in mechanical engineering, as well as in the assembly of railway wagons. The dimensions of the metal corner 50x50x5 mm or 50x50x6 mm allow you to assemble all kinds of frames, experiencing light loads. In other cases, a less durable version of 50 x 50 x 3 or 50 x 50 x 4 mm may be used. Such a corner weighs more, and therefore costs less.
Galvanized Steel Corner
Very often, this type of metal is used to assemble metal structures that are exposed to moisture during operation. Since ordinary steel is subject to corrosion, in this case, a special type of metal corner is most often used - galvanized. This option is quite expensive, but even in the most difficult conditions it can last for decades. The dimensions of the metal corner of this variety (the width and thickness of the shelves) are the same as in the usual.
Products of this variety are made most often from carbon steel. Galvanizing can be done in several ways. By simply immersing the corner in the melt, products with a protective layer thickness of 150 ΞΌm are obtained. Sometimes galvanizing is carried out in a rotating airtight container at high temperatures. In this case, zinc penetrates the upper layer of steel and, although the thickness of its layer is also equal to 150 microns, it holds much better. Steel can also be coated with this metal by spraying. In this case, it is possible to apply a much thicker layer of zinc - up to several millimeters.