scope:

Specifies for seamless and welded circular steel tubes for general purposes (e.g. mechanical, pressure and structural applications), the following: - preferred dimensions for outside diameter and wall thickness in milimetres and - masses per unit length in kilogrammes per metre of plain end tube. The outside diameters are classified into three series reflecting the availability of accessoires for piping systems (see Clause 4). This classificationD of outside diameters into different series and of preferred wall thicknesses indicates the range of steel tubes usually produced.