ST12 is actually ordinary cold rolled steel, ST12 belongs to the German standard (DIN1623), equivalent to EN10130 DC01, JS SPCC, the American standard ASTM A1008 CS.ST12 is ordinary cold rolled steel, ST13 stamping grade cold rolled steel, ST14 is deep drawing grade cold rolled steel, ST12 is expressed as an ordinary steel number, and q195, spcc, DC01 grade material is basically the same.