CRB800 steel -CRB800 ribbed steel cold-rolled ribbed steel bars -CRB550 -CRB800 cold-rolled ribbed steel bars - Ding Xun Hebei Wire Mesh Products Co. CRB800 cold-rolled ribbed steel cold-rolled ribbed steel is hot rods by cold three sides or both sides reinforced transverse ribs after rolling on its surface with an evenly distributed along the length direction. Grade cold-rolled ribbed steel bars and reinforced by the CRB minimum tensile strength constitute .C, R, B cold-rolled (cold rolled), ribbed (ribbed), steel (bar) three words in English, the first letter of each . Cold-rolled ribbed steel bars into: CRB550, CRB650, CRB800, CRB970, CRB1170 five grades. Cold-rolled ribbed steel nominal diameter: the equivalent cross-sectional area equal round bar nominal diameter. CRB550 steel nominal diameter range of 4-12mm. CRB650 or more grades of nominal diameter 4,5,6mm. CRB550 grade steel is appropriate for ordinary reinforced concrete structures in steel bars, welded steel mesh, stirrups, reinforced and prestressed concrete structures constructed by the non-prestressed reinforcement. CRB650, CRB800, CRB970, CRB1170 prestressed reinforced concrete structure is appropriate for the prestressing reinforcement. The company conventional product specifications are as follows: the production of standard specifications diameter shape CRB550 3--12 rod straight, thread GB13788-2008 CRB650 5 6 CRB800 3-12mm threaded rod performance grades Mpa elongation of not less than,% no less than bend 180 ° repeated bending test frequency relaxation rate, the initial stress 1000h,% not more than 10h, no more than CRB550 550 8.0 ----- D = 3d ----- ----- ----- CRB650 650 - --- 4.0 ----- 3 8 5 CRB800 800 ----- 4.0 ----- 3 8 5 CRB970 970 ----- 4.0 ----- 3 8 5 CRB1170 1170 ---- - 4.0 ----- 3 8 5