What is the difference between three - grade steel and other grades?
Three rebar is the new standard name for HRB400 steel, three steel for the old, as a kind of hot rolled ribbed bar. In construction, three - grade rebar is called the past.
1, different grades of steel (chemical composition is different). HRB335 grade steel is 20MnSi (20 manganese silicon); HRB400 grade steel bars are 20MnSiV or 20MnSiNb or 20MnTi etc.;2, strength is different, HRB335 grade steel tensile and compressive design strength is 300MPa, HRB400 grade steel tensile and compressive design strength is 360MPa.
Because of the difference of chemical composition and ultimate strength of steel bars, they are different in toughness, cold bending, fatigue resistance and so on.
