A steel tube is a hollow cylindrical structure made from steel, which is an alloy of iron and carbon. These tubes are commonly used in construction, manufacturing, and various engineering applications due to their strength and durability. They can be produced in different sizes and thicknesses, making them versatile for various uses. Steel tubes can be categorized into two main types: seamless and welded. Seamless tubes are made from a solid round steel billet, while welded tubes are formed by rolling steel sheets and welding the edges together. Both types are essential in industries such as automotive, aerospace, and plumbing.