In construction engineering, round steel and screw steel are popular terms for different kinds of steel bars. There are five main differences between them:
1. Different shapes. The outer surface of round steel is smooth; the outer surface of threaded steel has spiral ribs.
2. Different production standards. In the current standard, round steel refers to HPB235 steel bar, its production standard is "Hot Rolled Smooth Steel Bar for Reinforced Concrete" (GB13013); Threaded steel refers to HRB335 and HRB400 steel bar, its production standard is "Hot Rolled Ribbed Steel Bar for Reinforced Concrete" (GB1499).
3. Different strength. The design strength of round steel (HPB235) is 210 MPa; the strength of threaded steel is higher than that of round steel, the design strength of HRB335 is 300 MPa; and the design strength of HRB400 is 360 MPa.
4. Different grades of steel (different chemical compositions). Round steel (HPB235) belongs to carbon steel, steel grade is Q235; threaded steel belongs to low alloy steel, HRB335 steel bar is 20MnSi (20MnSi); HRB400 steel bar is 20MnSiV or 20MnSiNb or 20MnTi, etc.
5. Physical and mechanical properties are different. Because of the difference of chemical composition and strength of reinforcing bars, the physical and mechanical properties of reinforcing bars are different. The cold bending performance of round steel is better, it can be used as 180 degree bending hook, and threaded steel can only be used as 90 degree straight hook; the weldability of round steel is better, using ordinary carbon welding rod can be used, threaded steel should use low alloy welding rod; the toughness and fatigue resistance of threaded steel is better than that of round steel.
Above is the difference between rebar and threaded steel. I hope it will be helpful to you. For more information about Jinan rebar wholesale, please click on our website to consult: http://www.jzqgc.com./