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.外形不同。圆钢的外表面是光滑的；螺纹钢的外表面带有螺旋形的肋。

　　1. Different shapes. The outer surface of round steel is smooth; the outer surface of threaded steel has spiral ribs.

　　2.生产标准不同。在现行标准中，圆钢指HPB235级钢筋，它的生产标准是《钢筋混凝土用热轧光面钢筋》（GB13013）；螺纹钢一般指HRB335及HRB400级钢筋，它的生产标准是《钢筋混凝土用热轧带肋钢筋》（GB1499）。

　　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.强度不同。圆钢（HPB235）的设计强度为210MPa；螺纹钢的强度较圆钢要高，HRB335的设计强度为300MPa； HRB400的设计强度为360MPa。

　　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.钢种不同，（化学成份不同）。圆钢（HPB235）属碳素钢，钢种是Q235；螺纹钢属低合金钢，HRB335级钢筋是20MnSi(20锰硅)；HRB400级钢筋是20MnSiV或20MnSiNb或20MnTi等；

　　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.物理力学性能不同。由于钢筋的化学成份和强度的不同，因此在物理力学性能方面有所不同。圆钢的冷弯性能较好，可以作180度的弯钩，螺纹钢只能作90度的直钩；圆钢的可焊性较好，用普通碳素焊条即可，螺纹钢须用低合金焊条；螺纹钢在韧性、抗疲劳性能方面较圆钢好。

　　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.

　　以上就是钢筋和螺纹钢的区别介绍，希望对您有所帮助，更多济南钢筋批发的相关内容可以点击我们的官网进行咨询：http://www.jzqgc.com/

　　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./