Round-seam electric-welded pipes made depending on the diameter: from 10 to 530 mm according to GOST 10705-80; from 478 to 1420 mm according to GOST 10706-76. Thus, the total range of the outer diameter is from 10 to 1420 mm, the wall thickness is from 1 to 32 mm. The range of electric-welded straight-seam round pipes complies with GOST 10704-91. As the material for the manufacture of electric-welded pipes, steel grades are used: St2sp, St2ps, St2kp, St4sp, St4ps, St4kp (according to GOST 380-94) and 10ps, 20, 35, 45, 08kp (according to GOST 1050-88). Products are made of unlimited length: with a diameter of up to 30 mm - at least 2 m; with the diameter of St. 30 to 70 mm - not less than 3 m; with the diameter of St. 70 to 152 mm - not less than 4 m; with the diameter of St. 152 mm - not less than 5 m. Measured length: with a diameter of up to 70 mm - from 5 to 9 m; with the diameter of St. 70 to 219 mm - from 6 to 9 m; with the diameter of St. 219 to 426 mm - from 10 to 12 m. With a diameter of over 426 mm, electric-welded pipes are made only of unmeasured length. The common points of these standards are pipe rationing according to quality indicators into groups: A - with rationing of mechanical properties; B - with rationing of chemical composition; B - with rationing of mechanical properties and chem. composition; G - without rationing fur. properties and chem. composition, but with the regulation of hydraulic pressure. On products with a diameter of 57 mm or more, one transverse seam is allowed. Products with a diameter of 820 mm or more should have two longitudinal and one transverse seam. The outer burr on the product must be removed. The mass of a running meter of products can be calculated by the formula, taking the density of steel equal to 7.85 g / cm3. Please note that for products in accordance with GOST 10706-76, the mass of a running meter increases by 1% due to the strengthening of the seam. Separately, spiral-seam products of large diameters can be noted for which GOST 8696-74 exists. The maximum deviations in the wall thickness of spiral-seam products must correspond to the maximum deviations for the metal thickness provided by GOST 19903-74 for the maximum width of coiled and sheet steel. The size range of spiral seam products is from 159 to 2520 mm. Also, specialized products include main products - this is an electric-welded pipe for the construction of gas and oil pipelines, oil pipelines, technological and field pipelines. They are manufactured according to GOST 20295-85 in the range of diameters 159 - 426 mm.