16Mn is a low-alloy high-strength structural steel: containing 0.1%-0.25% carbon, with main alloying elements such as manganese, silicon, vanadium, niobium, and titanium, etc.; its total alloy content is less than 3%. It is divided into four grades of strength: 300, 350, 400, and 450 MPa. The main grades are Q295, Q345, Q390, Q420, and Q460. "Q" is the uppercase pinyin initial of "qu" (yield), the following number represents the yield point (σs) value of the grade, and the subsequent symbol indicates the classification of A, B, C, and D based on the content of impurities (sulfur, phosphorus) and the change of carbon and manganese elements from high to low. Grades A and B are commonly referred to as 16Mn.