The 16Mn precision tube has a carbon content of 0.1%-0.25%, and the main alloying elements manganese, silicon, vanadium, niobium and titanium are added; its total alloy content is less than 3%. According to the strength, it is divided into 4 levels of 300, 350, 400 and 450MPa. There are mainly Q295, Q345, Q390, Q420, Q460. ："Q" is the initial Chinese pinyin of the word "qu" for yielding, and the following number is the minimum yield point (σs) value of the grade, and the following symbol is based on the increase in the content of impurity elements (sulfur, phosphorus) of the steel It is divided into four grades A, B, C, D when it is low and with the change of carbon and manganese elements. Among them, A and B grade steels are usually called 16Mn. Precision tube is a seamless steel tube with high precision and high brightness produced by cold drawing or cold rolling process. Its inner and outer diameter dimensions can be accurate to within 0.2mm. When the bending and torsion strength are the same, the weight is lighter, so it is widely used in the manufacture of precision mechanical parts and engineering structures. It is also often used to produce various conventional weapons, barrels, and shells.