Roll Tube Process or Tube rolling:
The tube rolling process or roll tube is used to produce long and thick- walled continuous tubing. In this rolling is mainly used to producing seamless tubes. It tube rolling machine having two tapered rolls called piercing rolls and rotate in same direction. Round shape heated billet of steel is passed in between the taper rolls over a mandrel. The mandrel is hold in place by long rod, although this technique has been develop in the mandrel remain in this place without rod. When the billet is Centre punched or providing a small drill hole on one end and heat by proper temperature. Then pushed in forward direction into rolls. The rolling grip the billet and pulling it further into them.
The axes of rolling is crossed, so they are revolve the billet as well as draw in forward to mandrel with force applied. The mandrel also having revolve of its own position. Which billet revolving motion and mandrel together with in axial advancement of billet it make helical effect of rolling on the material. It may be tubing of larger bore made, a second piercing size need a third piercing operation is done. The large size need a third piercing operation. The rough tubing subjected to rolling, sizing, rolling and etc to become a correct shape and size also providing good surface finish. That tubing is made in various metals such as steel alloy, aluminium, brass and copper etc.