The production process of small-diameter thick-walled seamless steel pipes is the same as that of seamless pipes, and can be divided into four basic methods: cold drawing, cold rolling, hot rolling, and thermal expansion. Small-diameter thick-walled steel pipes are mostly used in large-scale steel structure construction as the main support part (steel pipe pile), such as bridge piling, submarine piling, and high-rise building piling.

Tapered pipe refers to a tapered seamless pipe designed and manufactured with seamless steel pipe as raw material through special equipment and technology. The main material of the seamless tapered steel pipe is mainly carbon steel, but also stainless steel and alloy steel.

Seamless steel pipes have a hollow cross-section and are widely used as pipes for transporting fluids, such as pipes for transporting oil, natural gas, gas, water, and certain solid materials. Special-shaped seamless steel pipe is a general term for seamless steel pipes with cross-sectional shapes other than round pipes. Seamless square pipes (such as a500 square tube) and seamless rectangular tubes (a500 rectangular tube) also belong to special-shaped seamless steel pipes.

Structural seamless steel pipes are seamless pipes used for general structures and mechanical structures. Mainly used in the manufacture of pipes, containers, equipment, pipe fittings, etc.

The steel sheet pile is a kind of steel structure with linkages on the edge, and the linkages can be freely combined to form a continuous and compact retaining wall or water retaining wall. Steel sheet piles can be divided into hot-rolled/tensile steel sheet piles and cold-formed steel sheet piles according to their different processing and manufacturing techniques.

Carbon steel pipes are made of steel ingots or solid round steel through perforation into capillary tubes, and then made by hot rolling, cold rolling or cold drawing. According to the production method, carbon steel pipes can be divided into two categories: seamless steel pipes and welded steel pipes. Non-metallic inclusions are non-metallic substances contained in carbon steel pipes that are different from those of the base metal. It destroys the continuity and isotropy properties of the metal matrix.