Hot-rolled unequal shelf gost 8510 86. Production of corners with shelves of different widths

The unequal shelf GOST 8510-93 is one of the main elements of metal structures. Appearance resembles the letter "G", where one shelf is larger than another. Two sides of the corner intersect at right angles. The product is manufactured in accordance with GOST 8510-93.

Production of corners with shelves of different widths

Steel corners have high strength and practicality. Such positive qualities are affected by their manufacturing method. The unequal steel angle is obtained by hot rolling (GOST 8910-93). A billet consisting of carbon or low carbon steel is rolled under high pressure. Products pass control for compliance with the parameters specified in state standards. Defective corners are sent for recycling.

Types of unequal angles

Based on the assortment of unequal corners, they differ from each other:
- In size. The corner number indicates the width dimensions of both shelves in centimeters. Numbers are written through a fraction. The length of the product varies from 4 to 12 meters and can be measured or unmeasured in a batch. The smallest corner size is designated 3/2, and the largest is 20 / 12.5.
- According to the composition of the material.
- By precision manufacturing (normal or high).

GOST 8510-93 regulates the maximum possible deviations in terms of curvature and twisting. The curvature of the corner is allowed no more than 0.4% of its entire length.

Use of unequal corners

Due to the different widths of the shelves of the product, it is often used in construction, where the widest side of the corner takes on a large load. A shorter shelf is affected by less force. The use of unequal corners greatly facilitates the building structure.
When it becomes necessary to buy unequal corners, you should be aware that they can differ from each other in the composition of the material. In construction, corners with a low carbon content in steel are often used. They are easily welded and have high strength (example St09G2S).
If the name of the corner contains only its overall dimensions, then it is made of ordinary steel. The chemical composition of steel grades is determined by GOST 380-94.

Depending on the size and type used in the manufacture of the material, the price of the finished product is determined. A complete list and cost are presented on our website.

Date of introduction 01.07.87

1. This standard applies to hot rolled equal-angle steel angles.

The standard fully complies with ST SEV 255-76.

2. Dimensions of corners, cross-sectional area, reference values \u200b\u200bfor axes and mass of 1 m of corners should correspond to those indicated in the drawing and in table. 1.

Table 1

Symbols for the drawing and table. 1:

AT -the width of the larger shelf;

b -thickness of a smaller shelf;

l -shelf thickness;

R - radius of internal rounding;

r -radius of curvature of the shelves;

J - moment of inertia;

i - radius of inertia;

x 0, y 0 -distance from the center of gravity to the outer edges of the shelves;

J xy - centrifugal moment of inertia.

3. According to the accuracy of rolling, the corners are made:

AND- high accuracy;

AT - usual accuracy.

4. The maximum deviations in the dimensions of the corners should not exceed those indicated in the table. 2.

table 2

5. The maximum deviations in the dimensions of the corners made on mills not equipped with rigid stands should not exceed those indicated in the table. 3 to 01/01/93.

(Amended edition, Amendment No. 1).

6. By agreement between the manufacturer and the consumer, the maximum deviations in the thickness of the shelf may be replaced by the maximum deviations in mass equal to%.

7. Deviation from the right angle at the apex shall not exceed 35 ".

Table 3

8. The blunting of the outer corners of the shelves (including the angle at the apex) is not controlled.

At the request of the consumer, the blunting of the external corners of the shelves (including the angle at the apex) should not exceed:

0.3 shelf thickness - for corners up to 10 mm thick incl .;

3.0 - for corners of st. 10 to 15 mm incl .;

5.0 - for corners with a thickness of st. 16 mm.

9. Corners are made from 4 to 12 m long:

measured length;

multiple measured length;

unmeasured length;

limited length within unmeasured;

measured length with non-dimensional lengths of not more than 5% of the mass of the batch;

multiple measured length with unmeasured lengths of not more than 5% of the mass of the batch.

It is allowed to make corners longer than 12 m.

8; 9. (Amended edition, Amendment No. 1).

10. The maximum deviations along the length of the corners of the measured length or multiple measured length shall not exceed in millimeters:

30 - with a length of 4 m;

50 - with a length of more than 4 m to 6 m;

70 - with a length of more than 6 m;

at the request of the consumer +40 mm - for corners longer than 4 to 7 m:

5 mm for every 1 m over 7 m.

11. The curvature of the corners should not exceed 0.4% of the length.

At the request of the consumer, angles are produced whose curvature does not exceed 0.2% of the length.

For corners No. 2.5 / 1.6 to 5.6 / 3.6 incl. the curvature is checked at a length of 1 m.

12. Twisting around the longitudinal axis is not allowed.

13. The dimensions of the cross section of the corner are checked at a distance of at least 500 mm from the end of the rod.

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of Metallurgy of the USSR, Gosstroy of the USSR

2. APPROVED AND IMPLEMENTED BY Decree of the USSR State Committee for Standards dated 10.15.86 No. 3082

4. The validity period has been lifted according to the protocol No. 7-95 of the Interstate Council for Standardization, Metrology and Certification (IMS 11-95)

5. EDITION as Amended No. 1, approved in December 1990 (IMS 4-91)

When constructing reinforcing structures with increased stiffness characteristics, reinforcing concrete, joining handrails, organizing jumpers, steel unequal corners are used. Hot rolled products are in demand in both civil and private construction. They are used in interior design, shipbuilding and automotive industry, in the construction of small architectural objects. Metal products of this type are widely used even in the manufacture of furniture, decoration of premises. Such an extensive scope of use is due to the increased strength properties of the hot-rolled corner. It is manufactured in accordance with GOST 8510-86, which describes the dimensions, cross-sectional area and other parameters of the product.

Fig. 1. Appearance of hot-rolled steel unequal angle

Hot rolled unequal ragock - L-shaped profile from various steel grades. Its distinguishing feature is the side shelves of different sizes - one bigger than the other. According to the standard 8510-86, solid metal rolling is made of:

• Carbon steel (grade 09g2s, st3kp, St0-St6, st4kp, st4ps and 3sp5);
• Low alloy steel (grades 15KHSND, 08G2S, 15G2AFDPS, 16GS, 10KHSND, 12GS, 14KHGS).

Other steel grades are also used. Different sizes of product shelves are effectively used in the construction of arched structures, roofing trusses, etc. Hot-rolled metal products are produced by hot rolling of steel billets. It is passed between the rolls of the rolling mill. Production technology allows you to get a corner with an external pointed angle equal to 90 ’.

Fig. 2. The main quantities described by GOST 8510-86

Dimension of angles, reference values \u200b\u200bfor axes, cross-sectional area, mass, must correspond to those indicated in table 1.

The weight of 1 m of the product depends on the cross-section of the profile - from 1.16 cm 2 to 49.77 cm 2. When calculating the mass on the basis that the density of the steel should be at least 7.85 g / cm 3. In the manufacture of standard products, the weight of 1 m of the corner will vary from 0.91 kg to 39.07 kg. Calculation of the mass according to the density of the metal is used in the production of rolled metal at the request of the consumer.

What parameters does the standard 8510-86 describe?

The current GOST 8510-86 describes:

• ratio of lengths of larger and smaller shelves;
• radii of curvature of the ends of the shelves and the inner corner;
• shelf thickness;
• radius and moment of inertia;
• centrifugal moment of inertia.

Fig. 3. Designations of the described quantities

For metal rolling to comply with the standard, the distance from the outer edges of the shelves to the center of gravity must also be taken into account in its production. GOST determines the length of the product. It can vary from 4 to 12 m. In this case, a hot-rolled steel profile can have:

• measured and unmeasured length;
• multiple measured length;
• within unmeasured limited length.

It is allowed to produce rolled metal and of a larger size (length over 12 m), but at the same time, the value of its curvature should still not exceed 0.4% of the length. The standard describes profiles of high (A) and ordinary (B) accuracy. For both types of products limit deviations in dimensions apply. They are listed in the table below.

Tables 2 and 3. Limit deviation of values

Characteristics of corners and shelves as standard

Standard 8510-86 states that the right angle (external, made up by the sides of the profile) at the apex cannot deviate from 90 ′ by more than 35 ’. At the same time, the blunting of the external corners of the shelves is not controlled by GOST. But in the manufacture of products at the request of the consumer, you must adhere to the following recommendations for blunting:

• 0.3 of the shelf thickness for corners up to 10 mm thick;
• 3.0 - for corners 10-15 mm thick;
• 5.0 - for corners more than 16 mm thick.

The table below shows the dimensional characteristics described by the standard of the most popular unequal hot-rolled steel corners. In the manufacture of products, the specified parameters cannot be exceeded.

Table 2. Technical characteristics of popular types of profile

For corners of unequal measured and multiple measured lengths, length deviations should not exceed:

• +30 mm - products up to 4 m;
• +50 mm - for four and six-meter profiles;
• +70 - if metal rolling is more than 6 m.

In the production of hot-rolled steel corners at the request of a consumer with a length of 4-7 m, the deviation should not exceed 40 mm. Then +5 mm for each subsequent meter.

How hot-rolled steel unequal corners are designed in accordance with GOST requirements is shown in the video.