Welded square pipe, the various assortment of which allows to pick up a product with necessary geometrical parameters, is carried out according to requirements, which contain GOST 30245-2003. Replacing outdated GOST 30245-94, this normative document defines the requirements for assortment and geometric parameters not only square, but also profile rectangular pipes, also belong to the category of welded.
Square steel pipe
Get acquainted and download GOST 30245-2003 and GOST 30245-94
Get acquainted with the content of the state standard document 30245-2003, which regulates the basic parameters, nuances of manufacturing and operation of square pipes, as well as download this GOST as low as possible.
GUEST 30245-2003
GUEST 30245-2003 Profiles steel bent closed welded square and rectangular for building constructions. Specifications
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Quite often, aiming to get acquainted with the range of square pipes, people are looking for GOST 30245-94, which is currently out of date, that he was replaced by a newer document of state standard. But if you still want to compare and find out, which changes have been made, then this GOST can be downloaded for free below.
GUEST 30245-94 Profiles steel bent closed welded square and rectangular for building constructions. Specifications
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Production of square profile pipes according to GOST
GUEST 30245-2003 is an official normative document, which determines not only the size of square pipes, but also the technological features of their production. Naturally, that profile pipes, which are made by hand, it is strictly forbidden to use in capital construction. Such products often do not meet the requirements of GOST not only for geometric parameters, but also in strength. in addition, they are not labeled and are not considered goods, admitted to public sale.
Line for the manufacture of profile pipes
Basic geometric parameters of the product
The state standard stipulates a whole list of geometric parameters, which must correspond to the metal profile pipes, having a square cross section. Such parameters include:
- h - dimensions of the sides or height of the profile;
- b is the width of the profile (this parameter may differ from the height, if the pipe has a rectangular cross section);
- t is the wall thickness;
- R is the radius of curvature (external), measured at the intersection of the walls.
Parameters of cross section of square profiles according to GOST 30245-2003
The normative document states, that the geometric parameters of the profile square tubes may have deviations, which must be within the limits below.
On the outer radius of rounding
- for products with a wall thickness up to 6 mm - 1.6t-2.4t;
- for products with wall thickness 6-10 mm - 2.0t-3.0t;
- for pipes, whose wall thickness is greater 10 mm, - 2.4t-3.6t.
In height / the width of the sides of the steel pipe
- for pipes, height / the width of the sides of which is 100 mm and less, - from ± 0,5 mm to ± 1%;
- for products with the sizes of the parties, exceeding 100 mm, — ± 0,8%.
At the corner of the intersection of the sides of the pipe (900), measured in cross section of the profile
- ± 1030 ?.
The dimensions of the sides and the wall thickness of the square pipe
According to the requirements of GOST, the sizes of the parties of profile pipes, having a square cross section, may vary in the range 50-300 mm. In the range of these products, each profile size corresponds to a certain wall thickness: the larger the dimensions of the sides of the steel square tube, especially with greater wall thickness (this parameter varies in the range 2-14 mm) they are produced.
All parameters, which must correspond to the square section pipe, are given in the table.
Basic parameters of square pipes
Steel profile pipes, having a square cross section, can be carried out not only according to GOST, but also according to the Technical Specifications, these are specially developed Technical Conditions. In accordance with the requirements of this document, which is approved by the state regulatory body, pipes with a square profile can be made in non-standard sizes (length, the size of the walls and their thickness). Such products, in the marking of which there is an abbreviation TU, are made mainly by special orders.
When considering and approving the Technical Conditions, the state controlling body assesses the degree of safety of products with non-standard sizes., provides for its mandatory testing, and also determines, whether its release on the equipment is possible, which the enterprise is equipped with.
Requirements for the length of the square pipe
Steel profile pipes, having a square cross section, in accordance with the requirements of the regulatory document, can be produced in excess, dimensional, as well as multiples of measured length. The following requirements must be observed when cutting, which are regulated by GOST.
- The length of the cut profile products should be in the range 4-13 m.
- The most common lengths of pipes, released from the manufacturer's warehouse, is 6 and 12 meters.
- Products of measured and multiple measured length must not have a deviation of more than one 60 mm.
- Length of pipes, released from the manufacturer's warehouse, determined by the customer, but it must be within, stipulated in the normative document.
Long square pipes
How to understand labeling
In the marking of square profile steel pipes, requirements to which are also stipulated in the Guest, the following characteristics are displayed.
At the top of the marking (numerator):
- geometric parameters of the product labeled batch (height, width, wall thickness);
- normative document number, according to which the product is made.
At the bottom of the label (denominator):
- steel grade, of which it is made ??profile pipe;
- normative document number, which corresponds to the material of manufacture of the product.
Marking of square pipes contains information about the parameters of the product
Consider as an example, how the profile pipe of square section with the sizes of the parties is marked 100 mm and wall thickness 6 mm, made ??from steel S390K:
100x100x5 GOST 30245-2003 / С390К ГОСТ 2772-88.
Performance characteristics and applications of square pipes
Performance characteristics, which have steel pipes with a square profile, are defined as the material of their manufacture, and features of their design, which is a closed profile, formed of a metal strip. The result is a pipe, having a small weight, but is able to withstand significant bending and torsional loads. Requirements for its strength, as well as test methods, by which they are controlled, also stipulated in Guests.
Profile pipes are often used in load-bearing frames of various structures
Due to the exceptional strength, low weight and manufacturability profile metal pipes with a square cross section are widely used in many fields of human activity. So, these products are most actively used in:
- construction of buildings for various purposes (from such pipes the facilitated bearing designs for warehouses are mounted, shops, greenhouses, winter gardens, farm, canopies, etc.);
- reconstruction of construction sites (by means of square steel pipes frameworks of roof designs and overlappings are created, incoming groups, etc.);
- furniture production (cabinets, racks, shelves, tables, chairs, etc.);
- production of various mechanisms and devices in mechanical engineering;
- creation and installation of advertising structures.
Unlike pipes of round section, which under the influence of significant bending loads can not only bend, but also to collapse, products with a square profile at the same value and direction of loading only bend, and when it is removed return to its original state.
Choosing a square profile pipe to solve a particular problem, it is necessary to make all the necessary calculations in advance. As a result, it will become clear, the product with which geometric parameters of the profile will be able to withstand the load, which will be accounted for by him.
features of production
Pipes with a square profile, that meet the requirements of GOST 30245-2003, can be made of different grades of sheet steel, which include:
- steels of carbon group of general purpose and low-alloy grades, available with sheet thickness 3 mm for GOST 27772;
- steel of general purpose carbon grades, produced according to GOST 14637 (sheet thickness 4 mm and more) and according to GOST 16523 (sheet thickness 3 mm);
- carbon quality steel grades 10, 15 and 20, issued according to GOST 1050;
- steel low-alloy grades, issued according to GOST 19281 (sheet thickness 4 mm and more) and according to GOST 17066 (sheet thickness 3 mm).
Profile pipes prepared for transportation are stored in the factory warehouse
Production of steel square pipes of this category is carried out in several stages.
- Sheet metal, originally in rolls, unwind and cut into strips of the required width.
- The ends of the resulting strips are welded to form a long strip.
- The steel strip is fed to the forming machine, where by means of special rollers from it the product with a square profile is formed.
- Longitudinal connecting seam, obtained as a result of flexible, boiled.
- The lattice is removed from the weld (its height should not exceed 0,5-1 mm depending on the wall thickness of the product).
- Weld quality control is carried out, as well as the surface of the resulting pipe. After eliminating the shortcomings, if they are detected, the pipes are cut into pieces of the required length and sent for packaging.
Finished pipes undergo instrumental control of compliance with the requirements of GOST
In addition to the above technology, steel pipes with a square shape of the profile can be made by cold and hot deformation.
What else you need to know about steel pipes of square cross section
For each batch of pipes, shipped from the production plant, supporting documents must be issued, the main of which is the quality certificate. In such a document, certified by the stamp VTK enterprise-manufacturer, should contain the following information:
- manufacturer's name and trademark;
- data on the material of manufacture (steel grade and its physical and chemical properties);
- batch volume (the number of pipes and their length);
- batch number;
- the number of packages in the consignment;
- additional information about the order;
- date of manufacture.
The passport for the profile pipe must contain all the necessary information
For storage and subsequent transportation, the pipes are packed in bundles, the weight of each of which should not exceed 10 tons. If the pipes are long 3 m and less, then the bundle is tied with them in one place (in the middle), if more 3 meters - then in two. Tying bundles of pipes should not only ensure their compactness of storage and transportation, but also the ability to lift and move them with mechanized devices.
U GOST 30245-2003 not only the requirements for steel pipes of square section are determined, but also the period, during which they fully retain their technical and operational characteristics. Such a period, according to the specified regulatory document, is 2 years.
Naturally, steel profile pipes will fully retain all their characteristics only if, if in their production, storage and transportation met all the necessary conditions.