Cold drawn carbon steel wire used in construction is divided into A and B levels. Prestressing steel grade B steel wire is mainly used for small prestressed concrete members of the general framework for weld or banding, mesh or stirrups. Used wire prestressed concrete members, preference should be given Grade 3 or 4 hot-rolled steel wire rod drawing mill performed. This depends largely on the strength of steel raw material (hot rod) strength and elongation of the total amount of deformation after Stubbs is an important indicator to assess its quality such as elongation is too small, it could lead to use it reinforced prestressed concrete structures without significant deformation occurs harbinger of brittle fracture, so the system should be properly selected pull pull system passes to ensure that plastic wire. Used wire prestressed concrete members shall be sampled by mechanical disk performance testing, according to the performance requirements determine the level and groups, reasonable arrangement. Cold drawn low carbon steel is mainly used for small prestressed concrete members, such as beams, hollow floor, small poles, and rural buildings purlins and door frames and the like. ?