Inspection standard for Screw thread steel

　　1. Specifications

　　The specification requirements of rebar shall be listed in the import and export trade contract. Generally, it shall include standard brand (type code), nominal diameter, nominal weight (mass), specified length and allowable deviation of the above indicators.

　　Rebar series with nominal diameters of 6, 8, 10, 12, 16, 20, 25, 32, 40 and 50mm are recommended in Chinese standards. The supply length is divided into fixed length and double length.

　　The selection range of fixed length of deformed steel bars exported from China is 6 ~ 12M, and that of deformed steel bars produced in Japan is 3.5 ~ 10m; If there are no requirements specified in the contract, the length of domestic screw thread steel is usually 9m and 12m.

　　2. Appearance quality of Screw thread steel

　　(1) Surface quality. The surface quality of deformed steel bar is specified in relevant standards. It is required that the end shall be cut straight, and the surface shall be free of cracks, scabs and folds, harmful defects in use, etc.

　　(2) Allowable deviation of overall dimension. The requirements for the bending degree of deformed bar and the geometry of reinforcement are specified in relevant standards.

　　3. Standard number of Screw thread steel

　　GB1499. 2-2007 (steel for reinforced concrete Part 2: hot rolled ribbed reinforcement)

　　GB1499. 2-2007 / xg1-2009 steel for reinforced concrete Part 2: hot rolled ribbed steel bar No. 1 amendment to national standard; GB / T 2101-2008 (general provisions for acceptance, packaging, marking and quality certificate of section steel).

　　GB1499. 1～GB1499. 3 (reinforcement for concrete); JIS g3112-87 (98) (bar steel for reinforced concrete); Jisg3191-66 (94) (shape, size, weight and allowable difference of hot rolled bar steel and coil steel); Bs4449-97 (hot rolled steel bars for concrete structures).