According to different production methods, it can be divided into hot rolled tubes, cold rolled tubes, cold drawn tubes, extruded tubes, etc.

1.1. Hot-rolled stainless steel seamless pipe are generally produced on automatic pipe rolling mills. The solid tube is inspected and cleaned of surface defects, cut to the required length, centered on the perforated end of the tube, and then sent to the heating furnace for heating and piercing on the punching machine. When the perforation continues to rotate and advance at the same time, under the action of the roller and the plug, a cavity is gradually formed inside the tube blank, which is called a capillary tube. And then sent to the automated rolling mill to continue rolling. Finally, the whole wall thickness is uniformed for the whole machine, and the diameter is sizing by the sizing machine to meet the specifications. The use of continuous tube rolling mills to produce hot rolled seamless steel tubes is a more advanced method.

1.2. If you want to obtain seamless pipes with smaller size and better quality, cold rolling, cold drawing or a combination of the two methods must be used. Cold rolling is usually carried out on a two-high rolling mill. The steel pipe is rolled in an annular pass formed by a variable cross-section circular hole groove and a stationary tapered plug. Cold drawing is usually carried out on a single-chain or double-chain cold drawing machine of 0.5-100T.

1.3. The extrusion method is to put the heated tube blank in a closed extrusion cylinder, and the perforated rod and the extrusion rod move together to extrude the extruded part of the smaller die hole. This method can produce steel pipes with smaller diameters.

This kind of steel pipe can be divided into two categories: stainless steel seamless steel pipe and stainless steel welded steel pipe (seam pipe). According to the different manufacturing process, it can be: hot-rolled, extruded, cold drawn and cold-rolled. The shape can be divided into round pipes and special-shaped pipes. Round steel pipes are widely used, but there are also some special-shaped stainless steel pipes such as square, rectangular, semicircular, hexagonal, equilateral triangle, and octagonal.

For steel pipes subjected to fluid pressure, hydraulic tests must be carried out to verify their pressure resistance and quality, and no leakage, wetting, or expansion under the specified pressure is qualified, and some steel pipes are also subject to crimping tests according to standards or requirements of the buyer. flaring test, flattening test.

Seamless stainless steel pipes, also called stainless steel seamless pipes, are made of steel ingots or solid tube blanks that are perforated into capillary tubes, and then made by hot rolling, cold rolling, or cold drawing. The specifications of seamless steel pipes are expressed in millimeters of outer diameter * Wall thickness