Specification Of Steel Pipe

(1) Specification: The specification requirements of spiral steel pipe shall be listed in the import and export trade contract. Generally, it shall include the standard grade (type code), nominal diameter of reinforcement, nominal weight (mass), specified length and the tolerance of the above indicators. Chinese standard recommends spiral steel pipe series with nominal diameter of 8, 10, 12, 16, 20 and 40 mm. The supply length is divided into fixed length and double length. The selection range of length of deformed steel bars exported from China is 6~12m, and that of deformed steel bars produced in Japan is 3.5~10m.
(2) Appearance quality: ① surface quality. The surface quality of deformed steel bars is specified in the relevant standards, and the ends shall be cut flat and straight, the surface shall be free of cracks, scabs and folds, and there shall be no harmful defects in use; ② Allowable value of overall dimension deviation. The requirements for the bending of deformed steel bars and the geometric shape of reinforcement are specified in the relevant standards. As specified in Chinese standards, the bending of straight bar reinforcement shall not be greater than 6mm/m, and the total bending shall not be greater than 0.6% of the total length of reinforcement.