Cold drawn steel production methods are roughly divided into cross rolling method (Mengneisiman France) and extrusion. Cross-rolling method (Mengneisiman method) is to use oblique roll tube perforation bad, then rolling it extends. This method of production speed, but higher on the tube workability requirements, mainly for the production of carbon steel and low alloy seamless steel pipe. Extrusion rule is perforated tube or ingot perforation machine, and then into a seamless steel pipe extruder, this method is lower than the efficiency of cross rolling method for the production of high-strength alloy seamless steel pipe. Cross-rolling method and extrusion billet or ingot must first heating, the production of cold drawn steel tubes known as hot-rolled. With the production of seamless steel thermal processing method may further cold sometimes needed. Cold, there are two ways: one is cold-drawing method is to extubation die tube drawing by drawing, so seamless steel tapers, elongation; Another method is the cold rolling method, it is within Bangladesh hot rolling mill Mann brothers invention is applied in cold working method. Cold working the tube drawing, a seamless steel pipe can be improved dimensional accuracy and finish processing, improve the mechanical properties of the material and the like. Seamless seamless steel (hot-rolled seamless steel pipe) production technology of seamless cold drawn steel tubes mainly accomplished by reducing the tension, the tension-reducing rolling process is a continuous process with no hollow base metal mandrel . In ensuring the quality of the premise of the mother pipe welding, pipe tension reducing overall process is the pipe is heated to 950 degrees Celsius, and then stretch reducing mill (stretch reducing mill total of 24 times) rolled into a variety of outside diameter and wall thickness of the finished pipe, use of this technology and the production of hot-rolled seamless steel pipe ordinary frequency differentiated by the nature of the heating furnace after its microstructure and mechanical properties of the weld and the parent can achieve exactly the same Moreover, by multiple passes of tension reducer rolling and cold drawn steel automatic control makes the dimensional accuracy (especially the tube wall thickness and roundness accuracy) than similar cold-drawn steel. Developed world production of seamless steel tubes, boiler tube, seamless pipe has been widely adopted technology, with the development of society, the domestic hot-rolled steel cold drawn pipe gradually replace the situation has been formed. Flat iron manufacturer: http: //www.sfbiantie.com/index.php/list/sfbiantie/1225/cn/1225/1225.html shengfang furniture accessories manufacturers: http: //www.sfbiantie.com/index. php / text / sfbiantie / 1224 / cn / 1224 / 1224.html article unlimited business people finishing release!