The article Introduces the different of tolerances on dimensions,mechanical properties,surface quality of that between the new and last issue in Aluminium alloy extruded tubes-part 1:seamless tubes and Aluminium and aluminium alloy cold drawn(rolled) seamless tubes,and gives instruction of how technical requirement are determined the problems that will appear on alternate period.

The extruding technology for theφ48×6mm seamless thick walled tube,design of the extruding die and the application measure in production are briefly stated.

Through to the extruding technology innovation research of using 3500t hydraulic machine extruding seamless special pipe, broke through the traditonal design idea, designed the special extruding die.

The requirements of dimensions,mechnical properties,surface quality on aluminium alloy seam tubes are explained.

In order to strengthen the oil-field user’s confidence in the ERW casing made in China,the contrast study of the dimension control,residual stress,and pipe collapse pressure between ERW and seamless casing was conducted in this paper.

Present Status and Development of Alloy Steel Seamless Tube;

Analysis on stretch reducing rolling process of seamless tube by FEM;

Development of round billet of heat resistant stainless steel seamless tube for high pressure boiler