1) specification: the specification requirements of steel bars should be specified in the import and export trade contract. Generally, it should include the standard brand (model code), nominal diameter, nominal weight (mass), specified length and tolerance value of the above indicators.

China Standard recommends rebar series with nominal diameters of 8, 10, 12, 16, 20 and 40MM. Supply length is divided into fixed length and double length. The selection range of rebar length for export in China is 6 ~ 12m, and that for Japanese rebar is 3.5 ~ 10m.

(2) Appearance quality:

① Surface quality. The surface quality of steel bars is stipulated in relevant standards, which requires that the ends be cut straight, and the surface shall be free of cracks, scars and folds, and there shall be no harmful defects in use.

(2) Allowable value of overall dimension deviation. The requirements for the bending degree and geometric shape of steel bars are stipulated in the relevant standards. According to Chinese standards, the bending degree of straight steel bar is not more than 6MM/M, and the total bending degree is not more than 0.6% of the total length of steel bar.