Cold Drawn Seamless Steel Pipes are the tubes with high precision and good surface dimensions for mechanical structures and hydraulic equipment. The use of precision seamless tubes to manufacture mechanical structures or hydraulic equipment can greatly save processing time, improve material use, and improve product quality.

Production of cold drawn seamless steel tubes and method of manufacture

According to different production methods, it can be divided into hot rolled tube, cold rolled tube, cold drawn tube and extruded tube. The biggest difference between cold drawn seamless steel tubes and hot rolled seamless steel tubes is that the precision of cold drawn seamless steel tubes is better than the precision of seamless steel tubes. The general accuracy of cold drawn seamless steel tubes is about 20 wire, while hot rolling does not contain about 100 threads, thus cold drawn seamless tube are the first choice for mechanical processing industry and cutting industry.

1. Hot-rolled seamless tubes are generally produced on automatic rolling mills. The empty steel tube is inspected and surface defects are removed, cut to desired length, centered on the end of the perforated end of the tube blank, then sent to a preheater for heating and perforated on the punching machine. At the same time, it is constantly rotating and perforating. Under the influence of twisting and head, the cavity is gradually formed inside the empty tube, which is called capillary tube. Then send it to the automatic tube wrapping machine to continue spinning. Finally, the machine is thickened evenly by the sizing machine, and the sizing size (reduction diameter) of the sizing machine is reduced to meet the specifications. Hot rolled seamless steel duplex pipe production by continuous mills is a more advanced method.


2. If you want to have a seamless tube of smaller size and better quality,


3. Extrusion method: The empty tube to be heated is placed in a closed extrusion cylinder, and the perforated rod moves with the extrusion rod to eject the extrusion from the smaller mold opening. This method can produce gi pipe, steel tubes with smaller diameters.

Cold drawn seamless steel pipes

1. Seamless tubes are widely used. General purpose seamless tube is rolled from ordinary carbon structural steel, low alloy structural steel or alloy structural steel, Titanium tube and has the largest output, and is mainly used as a pipe or structural part for conveying liquids.


2. According to the use of three types of supply:

A- According to the chemical composition and mechanical properties;

B- According to the mechanical properties;

C- According to the pressure water supply test. Steel tubes supplied in categories (A) and (B), if used to withstand liquid pressure, are also subject to hydrostatic testing.

3. Special purpose seamless tubes include copper nickel pipe,seamless tubes for boilers, geological seamless tubes, and petroleum seamless tubes.

Type

1. Seamless steel tubes can be divided into hot rolled tubes, cold rolled tubes, cold drawn tubes, and extruded tubes according to different production methods.


2. According to the inconel pipe shape, there are round tubes and tubes of special shape. In addition to the square tube and rectangular tube, the special shape tube contains an oval tube, semi-circular tube, triple tube, hexagonal tube, convex tube, plum shaped tube, and the like.


3. According to various materials, divided into regular carbon structural tube, low alloy structural tube, alloy structural tube, monel pipe, high quality carbon structural tube, and stainless tube and so on.


4. According to particular purposes, there are boiler tubes, oil pipes, hastelloy pipe, geological tubes, etc.