Seamless Steel Tubes

General information on seamless steel tubes

Seamless steel tubes are hollow sections with a round, square, rectangular or oval cross-section that are manufactured without a weld seam. These seamless pipes have a uniform shape and offer high pressure resistance and load capacity. Therefore, they are often used in steel and mechanical engineering as well as in pipeline construction and as pressure-stressed components in plant construction. Depending on the area of application and requirements, they are available in various steel materials, designs and dimensions.

Production of seamless steel tubes

To produce seamless round tubes, starting material, for example steel ingots or continuous round castings, is heated to forming temperature to produce an annular cross-section, pierced and passed through rollers. Afterwards, the tubes are often cold processed to achieve tighter wall thickness and diameter tolerances, a better surface quality or special material properties.
To produce seamless tubes with square, rectangular or oval cross-sections, seamless round tubes are usually formed into hollow sections with the corresponding cross-sections by hot rolling at forming temperature. If the pipes are to be given a specific corrosion resistance, surface quality or colour, they can then be galvanised, powder-coated or painted.

Where are seamless steel tubes used?

Seamless square and rectangular tubes are used as steel construction hollow sections in a wide variety of areas. Round steel tubes are available, for example, as seamless thick-walled tubes. These are hot-finished hollow sections with a large wall thickness for steel construction or for mechanical engineering and general technical applications. Seamless threaded tubes are particularly suitable for welding and thread cutting and can be provided with a pipe thread.
Seamless normal wall tubes are used, for example, as pressure-bearing components in plant and power station construction and boiler tubes are also suitable for pressure loads at elevated temperatures thanks to their very high temperature resistance. Areas of application for seamless steel tubes include:

• Steel construction
• Building construction
• Mechanical engineering
• Apparatus engineering
• Plant engineering
• Power plant construction
• Boiler construction
• Pipeline construction
• Chemical and petrochemical industry

Advantages of seamless steel tubes

• Good pressure and temperature resistance

• High mechanical strength
• Good static properties
• Very good weldability
• Good machinability
• Long service life
• Good recyclability