20g thick-walled seamless steel pipes are long steel bars with a hollow cross-section and no seams along the periphery. These pipes, with their hollow cross-section, are extensively used as pipelines for conveying fluids, such as oil, gas, water, and certain solid materials.

The 20G thick-walled seamless steel pipe is a GB/5310 standard steel grade (corresponding grades overseas: Germany's st45.8, Japan's STB42, and the US SA106B). It is commonly used for boiler steel pipes, with chemical composition and mechanical properties similar to those of 20 plates. This steel features certain strength at room and medium-high temperatures, low carbon content, excellent plasticity and toughness, and good cold and hot forming as well as welding properties.

20g thick-walled seamless steel pipes are mainly used for manufacturing high-pressure and higher parameter boiler pipe fittings, low-temperature superheaters, reheaters, economizers, and water walls; as well as small-diameter pipes for heating surfaces with wall temperatures ≤500°C, water wall pipes, economizer pipes, etc. Thick-walled pipes are used for steam pipes with wall temperatures ≤450°C, headers (economizer, water wall, low-temperature superheater, and reheater headers), and pipeline accessories with medium temperatures ≤450°C. Due to graphitization in carbon steel above 450°C, the long-term high-temperature use of heating surface pipes is limited to below 450°C. The strength of this steel within this temperature range meets the requirements of superheaters and steam pipes, and it has excellent anti-corrosion properties, as well as good plasticity, toughness, and welding properties for both cold and hot processing. Its application is widespread. The steel is used in the Iranian boiler (referring to a single unit) for the following parts: downcomer (28 tons), water-steam inlet (20 tons), steam connection (26 tons), economizer header (8 tons), and water-reducing system (5 tons). The remainder is used as flat steel and hanger material (approximately 86 tons).

20g thick-walled seamless steel tubes are long, seamless steel tubes with hollow cross-sections and no seams along the perimeter. These tubes have hollow sections and are extensively used as piping for conveying fluids such as oil, gas, water, and certain solid materials. Compared to solid steel products like round bars, seamless steel tubes have the same bending and torsional strength but are lighter in weight, making them an economical cross-sectional steel. They are widely used in the manufacturing of structural components and mechanical parts, such as oil drilling pipes, automotive drive shafts, bicycle frames, and steel scaffolding used in construction. The manufacturing of circular components from steel tubes enhances material utilization, simplifies production processes, saves materials, and reduces processing time, as seen in components like roller bearing rings and jack sleeves, which are now commonly made from steel tubes. Seamless steel tubes are also an indispensable material for various conventional weapons, with gun barrels and cannon tubes being made from them. Seamless steel tubes are classified into round tubes and non-standard tubes based on the shape of their cross-sectional area. Due to the larger circular area under the same perimeter, round tubes can convey more fluid. Moreover, the circular cross-section distributes stress more evenly when subjected to internal or external radial pressure, which is why the vast majority of seamless steel tubes are round.