Gives values of both plain end tubes for general purpose use and precision tubes. Its purpose is to give guidance on the selection of sizes for all activities concerned with the standardization of steel tubes, both nationally and internationally, to serve as a ready reckoner and to avoid the use by different countries of different masses for a tube of the same size. It is not applicable to tubes primarily intended to be screwed. This fourth edition cancels and replaces the third edition (1985), tables 2 and 3 of which have been technically revised by the addition of the outside diameter of 12.7 mm to series 2.