Q345 steel is China's standard low-alloy high-strength structural steel. The material has a minimum yield strength of 345 MPa (50 ksi) and a tensile strength of 470-630 MPa (68-91 ksi). Has better performance than Q235. According to GB/T 1591-2008, Q345 material has 5 quality levels: Q345A, Q345B, Q345C, Q345D and Q345E.