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。圓鋼的外表面是光滑的；螺紋鋼的外表面帶有螺旋形的肋。

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

　　2.生產標準不同。在現行標準中，圓鋼指HPB235級鋼筋，它的生產標準是《鋼筋混凝土用熱軋光面鋼筋》（GB13013）；螺紋鋼一般指HRB335及HRB400級鋼筋，它的生產標準是《鋼筋混凝土用熱軋帶肋鋼筋》（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.強度不同。圓鋼（HPB235）的設計強度為210MPa；螺紋鋼的強度較圓鋼要高，HRB335的設計強度為300MPa； HRB400的設計強度為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.鋼種不同，（化學成份不同）。圓鋼（HPB235）屬碳素鋼，鋼種是Q235；螺紋鋼屬低合金鋼，HRB335級鋼筋是20MnSi(20錳硅)；HRB400級鋼筋是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.物理力學性能不同。由于鋼筋的化學成份和強度的不同，因此在物理力學性能方面有所不同。圓鋼的冷彎性能較好，可以作180度的彎鉤，螺紋鋼只能作90度的直鉤；圓鋼的可焊性較好，用普通碳素焊條即可，螺紋鋼須用低合金焊條；螺紋鋼在韌性、抗疲勞性能方面較圓鋼好。

　　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.

　　以上就是鋼筋和螺紋鋼的區別介紹，希望對您有所幫助，更多濟南鋼筋批發的相關內容可以點擊我們的官網進行咨詢：http://www.ozhouu.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.ozhouu.com./