ISO 3545-1
Steel tubes and fittings; symbols for use in specifications; part 1: tubes and tubular accessories with circular cross-section
Stahlrohre und Formstücke; In Spezifikationen anzuwendende Symbole; Teil 1: Hohlprofile mit rundem Querschnitt
Responsible national committee
NA 178 BR - Steering Committee of DIN Standards Committee process and plant technology