In general, small diameter carbon steel pipe, known as small-diameter steel pipe, small diameter steel pipe can be divided into: seamless small-diameter steel pipe, welded small-diameter steel pipe. Generally we called the steel pipe that outer diameter is less than 89 as small-diameter steel pipe. According to different production methods can be divided into hot-rolled tubes, cold-rolled pipes, cold drawn tube, squeeze tubes, hot rolled seamless pipe is generally produced on automatic pipe mill.
The production process of small diameter carbon steel pipe is: Solid tube by check and cut into desired length, end to end surface of the perforation in the tube centering and then sent to the furnace heating in punch perforations in perforation while continuing to rotate and advance in the roll and immediate effect to remove surface defects. tube internal gradually formed a cavity known as the capillary, and then sent to the automatic rolling machine to continue rolling and finally by the machine are the entire wall thickness sizing, sizing machine, within specification, the use of continuous pipe mill producing hot-rolled small diameter steel pipe is a more advanced method of putting up a smaller size and better quality small diameter steel pipe, must adopt the method of cold-rolled cold-rolled cold drawn or both are usually on a two roll mill, small-diameter steel pipe in the variable section hole slot and does not move the cone-shaped head ring pass rolling, cold drawing is usually in a single chain or double chain drawing machine, extrusion is about to heat a good tube in closed extrusion perforated rods and extruded rod with movement within the cylinder, so that the extrusion extrusion from the die hole of smaller, this method can produce smaller diameter mild steel pipe.