St37 is a German grade, but it is a general grade, and there are several smaller grades.

Such as: St37-2 St37-3U St37-3n RSt-2 USt37-2 and so on.

ST37-2 is a German grade of carbon structural steel material
This material corresponds to my country’s equivalent of carbon structural steel Q235B (the old brand is: A3-B).

Another: Because this kind of steel is similar to 20 steel of my country's high-quality carbon structural steel, 20 steel can also be used instead.