This European Standard specifies,for seamless and welded circular steel tubes for general purposes(e.g. Mechanical.pressure and structural applications),as follow:preferred dimensions for outside diameter and wall thickness in millimetres and masses per unit length in kilogrammes per metre of pain end tubes.
EN 10220:2002 history
2002EN 10220:2002 Seamless and welded steel tubes - Dimensions and masses per unit length