Diameter tolerance of seamless steel pipe

Hot-rolled seamless steel pipe out diameter tolerance with different cold rolled steel after usually not needed for sizing. Therefore, cold rolling steel tube outer diameter of attention is an important indicator of quality. Pipe diameter hole tolerance and wear and rolling machine bouncing value is too large for. If the hole sizing with a serious wear and tear, the tube diameter increases is self-evident. Once the rolling force is too large, it will increase the value of rolling machine bouncing change the size of the roll nip, causing the pipe outside diameter tolerance. The size of the rolling force in addition to the original size of the tube, the metal itself is the size of the deformation resistance, but also with the rolling reduction ( reducing the amount of wall by volume and feed rate ) pipe size and the rolling surface of the tool quality, quality lubricating tube has a close relationship. All measures to reduce the rolling force are conducive to increased tube diameter precision, including the tube annealing; reduce rolling reduction; improve the quality and lubrication tube rolling tools, surface finish, etc. In addition, the use of high strength and hardness of the material to make pipe rolling tool, and to strengthen the rolling tool cooling and inspection, if found rolling tool badly worn, it should be replaced to prevent the pipe diameter tolerance.