1. The main features of seamless steel pipe are welding without seam and can bear great pressure. The products can be made from rough casts or cold drawn parts.
2.Precision steel pipes appear just in recent years, and there are strict tolerance and roughness between the inner hole and the outer wall size.
Cold drawn precision steel pipe features: 1). Have a smaller diameter. 2). Can be made in small quantities due to its high precision. 3). Finished cold drawn products have high precision and good surface quality. 4). The cross section of the steel pipe is more complicated. 5). The steel pipe has superior performance and its metal is relatively dense.
Hot-rolled precision steel pipes are made from continuous casting round billets or roughed slabs which are heated by walking beam furnace and then put into rough mill after high-pressure water descaling; rough materials are sent into finishing mill after cutting head and tail; we adopt the implementation of computer-controlled rolling and rough materials finally become straight rolls after rolling through laminar cooling and coiler. The heads and tails of the straight rolls are in shapes of tongue and fish, with relatively poor thickness, width accuracy and defects of wave shape, folding and tower shape. Its coil weight is heavy and the inner diameter of the steel coil is 760mm. After finishing line treatments of cutting head and tail, trimming and multi-pass straightening and skin passing treatments, recut or re-roll the straight roll, we will obtain finished products: hot-rolled steel plate, flat hot rolled coil and strip, etc. The hot rolled pickled steel plate can be made from hot rolled finishing coils by pickling, removing the scale and oiling.