Front-end loaders carry the hot band to the tubing mills. Welding OCTG Lone Star's welding and finishing facilities are the heart of its manufacturing process. The operation runs continuously from unwinding of the hot band to cutting and straightening of the tube. The ERW mill' s forming rolls push the steel strip's edges together to form the tube shape. An electric current then heats those edges.
Forms press the hot edges together to close the tube.
After the weld area is inspected ultrasonically, the tubes are cut and then fed through a battery of induction furnaces. Tubes for OCTG are cut to length, threaded, and coupled before being shipped. For demanding applications like specialty tubing, Lone Star will send tubes through a cold-drawing mill. Screeching noises warn all who approach that tremendous forces exist in the mill. At the draw mill, one end of the tube is milled to a smaller diameter than the rest of the tube.