DIN 1629 is the standard specifies the Seamless Circular Tubes of Non Alloys Steels with Special Quality Requirements. DIN 1629 applications the overheated boilers, as minimum thickness ferrite and seamless steel pipes, and as heat exchangers via austenitic pipes. The main products of steel / steel grade: DIN1629 ST37.0 DIN1629 ST44.0 DIN1629 ST52.0 Standards: API