(1) specifications: spiral steel pipe specifications should be set out in the import and export trade contracts. Standard grades should be included (type code), the bar nominal diameter, nominal weight (mass), regulation length and the tolerance values of indicators, such as the. Our standard recommended nominal diameters of 8, 10, 12, 16, 20, 40mm spiral pipe series. Delivery length and two kinds of double length of fixed length. Export rebar to length selected in the range of 6~12m, Japan produced rebar to length selected in the range of 3.5~10m.
(2) appearance: ① the surface quality. Standard provides for the surface quality of the steel, requires end to be cut straight, without cracks, scars on the surface and folded, harmful defects shall not be used; II dimension deviations allowed. Bending of rebar and steel geometry of the requirements provided for in the relevant standards. As our standard, straight bending of steel is not more than 6mm/m total total length of rebar bending is not more than 0.6%.