GOST 10704-91 Electrically welded steel line-weld tubes. Range

Scope of Application: Specifies the size range of electrically welded steel line-weld tubes, applicable to those used for transporting oil, gas, water, steam and other media as well as general structural purposes, excluding seamless steel tubes.
2. Dimensions and Specifications: Defines the outer diameter, wall thickness and theoretical weight per meter of the steel tubes. The common outer diameter ranges from 10 mm to 530 mm, and the wall thickness ranges from 0.8 mm to 5 mm. All dimensions must comply with the provisions in Table 1 of the standard.
3. Length Requirements
◦ Unfixed length: For tubes with an outer diameter less than 30 mm, the length shall be no less than 2 m; 30 mm to 70 mm, no less than 3 m; 70 mm to 152 mm, no less than 4 m; more than 152 mm, no less than 5 m.
◦ Fixed/multiple length: Can be produced as per customer requirements, which must comply with the relevant provisions for Class A and B tubes in GOST 10705.
4. Dimensional Tolerances: The outer diameter tolerance varies with the tube diameter. For example, the tolerance is ±0.3 mm for 12-30 mm outer diameter and ±0.8 mm for 57-108 mm outer diameter. The wall thickness tolerance is generally ±10%.
5. Material Requirements: Common carbon steel materials include Grade 08, 10, 15, 20 and St1-St3 series, which must meet the corresponding chemical composition and mechanical property requirements.