Small diameter seamless steel tube can be called small diameter seamless steel tube. Small diameter seamless steel pipe can also be divided into: seamless small diameter steel pipe and straight seam (also known as welding) small diameter seamless steel pipe. In 89 mm or smaller, 4 mm or larger steel pipe outer diameter, the general size is 1/2","3/4","1","1/1/4","1/2","2/2","3","31/2"can be collectively referred to as small diameter seamless steel pipe.


If you want to get smaller size and better quality seamless tubes, you must use cold-rolled cold-drawing or a combination of both. Cold rolling is usually carried out on a twin-roll mill. The steel pipe has circular cross section, variable cross section and fixed cone. The annular hole formed by rolling is usually extruded on a single or double chain cold drawing machine. The billet to be heated is placed in a closed extrusion cylinder. The rods move together to extrude the extrudate from smaller orifices, which results in smaller diameter steel tubes.