It is widely used in civil engineering construction such as houses, bridges and roads. Main production areas: Spiral pipe manufacturers are mainly distributed in North China and Northeast China. North China areas such as Shougang, Tangshan Iron and Steel, Xuanshan Iron and Steel, Chenggang, etc., and Northeast areas such as Xilin, Beitai, Fugang, etc., these two regions account for about thread More than 50% of the total steel output. SSAW steel pipes are widely used in natural gas, petroleum, chemical, electricity, heat, water supply and drainage, steam heating, penstocks for hydropower stations, thermal power generation, water sources and other long-distance transmission pipelines and engineering fields such as piling, dredging, bridges, and steel structures. SSAW steel pipes of good quality have thin and low transverse ribs, and often appear dissatisfied. The reason is that in order to achieve large negative tolerances, the reduction of the first few passes of the finished product is too large, the iron-type is too small, and the hole type is not full.