The bending diameter, weight and allowable deviation of heat-treated steel bars (GB 13014-1991)
In China, the bending diameter, weight and allowable deviation of heat-treated steel bars are stipulated by the national standard of GB 13014-1991.
1.Bending diameter
The bending diameter of heat-treated steel bars refers to the value obtained by bending the steel bar with two fulcrum points. The curvature is the radius of curvature of the arc obtained by connecting the two fulcrum points. The bending diameter of hot-rolled steel bars is 25mm and the bending diameter of cold drawn, rolled and extruded steel bars is 16mm.
2.Weight
The weight of hot-rolled steel bars is calculated by the theoretical weight formula according to the steel bar specifications, while the weight of cold drawn, rolled and extruded steel bars is calculated by the actual weight formula.
3.Allowable deviation
For the hot-rolled steel bars, the tolerances for the linear deviation and cross sectional deviation are 2.5%. For the cold-drawn, rolled, and extruded steel bars, the linear deviation generally does not exceed 2.5%. The allowable deviation for the sections below 6mm and for the sections over 6mm is 4%, and the permissible variation is 0.5-1.5% for each dimensional (length, width and thickness) of the cross-section.
In summary, its the Chinese national standard GB13014-1991 that stipulates the bending diameter, weight and allowable deviation of heat-treated steel bars.
