Thick-walled welded steel pipes refer to pipes with a wall thickness of 10mm or more, known as thick-walled welded pipes. Thick-walled welded steel pipes can be categorized into spiral thick-walled welded pipes and straight seam thick-walled welded pipes based on their production process and weld types.

Spiral-welded steel pipes utilize double-sided submerged arc welding technology, while straight seam thick-walled steel pipes include double-sided submerged arc welded straight seam pipes and high-frequency welded pipes. The major difference between them is the production diameter and whether or not welding wire is used. The theoretical weight calculation formula for thick-walled steel pipes is carbon steel: [(outer diameter - wall thickness) * wall thickness] * 0.02466 = kg/m (weight per meter), alloy: 0.02483, stainless steel: 0.02491. Thick-walled steel pipes have stronger compressive capacity due to their thicker walls and are suitable for load-bearing, supporting, and bridge pipes, as well as buried pipelines for transportation.