1. The main characteristic of seamless steel pipe is that it has no weld seam and can withstand great pressure. The products can be very rough as-cast or cold-drawn parts.

　　2. Precision steel pipe is the product that appears in recent years, mainly the dimension of inner hole and outer wall has strict tolerance and roughness.

　　The characteristics of cold drawn precision steel pipe are:

　　(1) the outside diameter is smaller.

　　(2) high accuracy can be used for small batch production.

　　(3) cold drawn products have high accuracy and good surface quality.

　　(4) the cross section of steel pipe is more complicated.

　　(5) the steel pipe has better performance and the metal is more dense.

　　The characteristics of hot-rolled precision steel pipe are:

　　Hot-rolled precision steel tube is made of continuous casting round tube slab or blooming slab, heated by walking-beam furnace, descaled by high-pressure water and then entered roughing mill. The roughing material is cut, tailed and then entered finishing mill, and controlled by computer. After finishing rolling, it passes through laminar cooling and coiling mill, and becomes direct coil. The head and tail of straight hair curl are often tongue-shaped and fishtail-shaped, and the accuracy of thickness and width is poor. There are often wave-shaped, folded edge, tower-shaped defects in the edge.

　　The coil weight is heavier and the inner diameter of the coil is 760mm. The direct-hair coil is processed by cutting head, cutting tail, cutting edge, multi-pass straightening, leveling and other finishing lines, and then the plate or rewinding is turned into: hot-rolled steel plate, leveling hot-rolled coil, longitudinal cutting strip and other products. The hot-rolled finishing coil should be pickled to remove the oxide scale and then become the hot rolled pickling coil after finishing the oil.

　　Precision seamless steel tube is also known as "high-precision finishing rolling bright seamless steel tube".

　　Process: High quality carbon steel, finish rolling, non-oxidizing bright heat treatment (NBK state), non-destructive testing, steel pipe inner wall with special equipment scrubbing and high pressure washing, steel pipe rust oil as anti-rust treatment, both ends of the cover for dust treatment.

　　Features: High precision, high smoothness, no oxide layer, high cleanliness, high pressure, cold bending, flattening, no cracks, can be used for various complex deformation and mechanical processing. The steel tube is brightly colored and has a high metallic luster.