(1) Specifications: The specifications of the spiral steel pipe should be listed in the import and export trade contract. It should generally include standard grades (category code), nominal diameters of steel bars, nominal weights (mass), specified lengths, and tolerances for the above indicators. China's standard recommended nominal diameter of 8,10,12,16,20,40mm spiral steel pipe series. The length of supply is divided into two types, length and size. China's export rebar length selection range of 6 ~ 12m, Japan rebar length range of 3.5 ~ 10m.
(2) Appearance quality: 1 Surface quality. The surface quality of the rebar has been specified in the relevant standards. It is required that the end should be cut straight, with no cracks, knots and folds on the surface, no harmful defects in use, etc.; The requirements for bending and reinforcing bar geometry of rebar are specified in the relevant standards. As stipulated in our country's standards, the straight bar reinforcement has a bending of no more than 6mm/m, and the total bending no more than 0.6% of the total bar length.