Spiral-welded steel pipes are those made by bending and deforming steel strips or plates into circular, square, and other shapes, then焊接 together, resulting in pipes with a seam on the surface. They can be categorized by welding methods, such as arc welding pipes, high-frequency or low-frequency resistance welding pipes, gas welding pipes, furnace welding pipes, and Bondi pipes, among others. They can also be classified by seam shape into straight seam welded pipes and spiral seam welded pipes. Welded steel pipes are used in the oil and gas drilling industry and mechanical manufacturing. Furnace-welded pipes can be used for water and coal gas pipelines, while large-diameter straight seam welded pipes are used for high-pressure oil and gas transmission. Spiral seam welded pipes are used for oil and gas transmission, pile foundations, bridge piers, etc. Welded steel pipes are more cost-effective and have higher production efficiency compared to seamless steel pipes.