It is a long steel material with a hollow section and no seams around it. Steel pipes have hollow sections and are widely used as pipelines for transporting fluids, such as pipelines for transporting oil, natural gas, gas, water and certain solid materials. Compared with solid steel materials such as round steel, steel pipes are lighter in weight when subjected to the same bending and torsional strength. They are an economical cross-section steel and are widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipes, automobile transmission shafts, and bicycles. Frames and steel scaffolding used in construction, etc.

Using steel pipes to manufacture ring-shaped parts can improve material utilization, simplify manufacturing work, save materials and processing man-hours, such as rolling bearing rings, jack sets, etc., which are now widely manufactured with steel pipes. Steel pipes are also an indispensable material for various conventional weapons. Gun barrels, barrels, etc. are all made of steel pipes. Steel pipes can be divided into round pipes and special-shaped pipes according to different cross-sectional area shapes. Since the circle area is the largest when the circumferences are equal, more fluid can be transported with circular tubes.

In addition, the circular cross section is relatively uniformly stressed when subjected to internal or external radial pressure. Therefore, the vast majority of steel pipes are round pipes. However, round tubes also have certain limitations. For example, under the condition of plane bending, round tubes are not as strong as square and rectangular tubes in bending strength. Square and rectangular tubes are commonly used in some agricultural machinery frames, steel and wood furniture, etc. Special-shaped steel pipes with other cross-sectional shapes are also required according to different uses.

1. Structural seamless steel pipe (GB/T8162-1999) is a seamless steel pipe used for general structures and mechanical structures.

2. Seamless steel pipes for fluid transportation (GB/T8163-1999) are general seamless steel pipes used to transport fluids such as water, oil, and gas.

3. Seamless steel pipes for low and medium pressure boilers (GB3087-1999) are used to manufacture superheated steam pipes, boiling water pipes for low and medium pressure boilers of various structures, superheated steam pipes, large smoke pipes, small smoke pipes and arch bricks for locomotive boilers. High-quality carbon structural steel hot-rolled and cold-drawn (rolled) seamless steel pipes for pipes.

4. Seamless steel pipes for high-pressure boilers (GB5310-1995) are high-quality carbon steel, alloy steel and stainless heat-resistant steel seamless steel pipes used for the heating surfaces of water tube boilers with high pressures and above.

5. High-pressure seamless steel pipes for fertilizer equipment (GB6479-86) are high-quality carbon structural steel and alloy steel seamless steel pipes suitable for chemical equipment and pipelines with working temperatures of -40~400℃ and working pressures of 10~30ma.

6. Seamless steel pipe for petroleum cracking (GB9948-88) is a seamless steel pipe suitable for furnace tubes, heat exchangers and pipelines in petroleum refineries.

7. Steel pipes for geological drilling (YB235-70) are steel pipes used by geological departments for core drilling. They can be divided into drill pipes, drill collars, core pipes, casings and sedimentation pipes according to their uses.

8. Seamless steel pipe for diamond core drilling (GB3423-82) is a seamless steel pipe used for drill pipe, core rod and casing for diamond core drilling.

9. Oil drilling pipe YB528-65) is a seamless steel pipe with internal or external thickening at both ends used for oil drilling. There are two types of steel pipes: threaded and non-threaded. Threaded pipes are connected with joints, and non-threaded pipes are connected with tool joints by the method of pairing.

10. Carbon steel seamless steel pipes for ships (GB5213-85) are carbon steel seamless steel pipes used in manufacturing ship grade | pressure-resistant piping systems, grade II pressure-resistant piping systems, boilers and superheaters. The working temperature of the carbon steel seamless steel pipe wall does not exceed 450°C, and the working temperature of the alloy steel seamless steel pipe wall exceeds 450°C.

11. Seamless steel pipe for automobile half-shaft casing (GB3088-82) is a high-quality carbon structural steel and alloy structural steel hot-rolled seamless steel pipe used for manufacturing automobile half-shaft casings and drive axle housing shaft tubes.

12. High-pressure oil pipe for diesel engine (GB3093-86) is a cold-drawn seamless steel pipe used to manufacture high-pressure pipes for diesel engine injection systems.

13. Precision inner diameter seamless steel pipe for hydraulic and pneumatic cylinders (GB8713-88) is a cold-drawn or cold-rolled precision seamless steel pipe with precise inner diameter for manufacturing hydraulic and pneumatic cylinders.

14. Cold-drawn or cold-rolled precision seamless steel pipe (GB3639-83) is a cold-drawn or cold-rolled precision seamless steel pipe with high dimensional accuracy and good surface finish used in mechanical structures and hydraulic equipment. The use of precision seamless steel pipes to manufacture mechanical structures or hydraulic equipment can greatly save machining hours, improve material utilization, and at the same time help improve product quality.

15. Stainless steel seamless steel pipe for structural use (GB/T14975-1994) is a hot-rolled ( Extruded, expanded) and cold drawn (rolled) seamless steel pipes.

16. Stainless steel seamless steel pipes for fluid transportation (GBTT14976-1994) are hot-rolled (extruded, expanded) and cold-drawn (rolled) seamless steel pipes made of stainless steel used to transport fluids.