The raw material for rolling No. 45 seamless tube is round tube billet. The tube embryo is cut by a cutting machine and the billet with a growth of about 1 meter is sent to the furnace by a conveyor belt for heating. The billet is fed into the furnace and heated at a temperature of about 1200 degrees Celsius. Fuel is hydrogen or acetylene. Temperature control in furnace is a key problem. After discharging the round billet, it must pass through the pressure perforator. The common piercing machine is conical roll piercing machine. This kind of piercing machine has high production efficiency, good product quality, large piercing diameter enlargement, and can pierce many kinds of steel. After piercing, the round billet is rolled, rolled or extruded by three rolls. After extrusion, the tube should be taken off and calibrated. The sizing machine rotates into the steel embryo to drill holes at high speed through the conical drill bit to form the steel pipe. The inner diameter of steel pipe is determined by the length of the outer diameter of the drill bit of the sizing machine. After sizing, the steel pipe enters the cooling tower and is cooled by spraying water. After cooling, the steel pipe will be straightened. After straightening, the steel pipe is sent to metal flaw detector (or hydraulic test) by conveyor belt for internal flaw detection. If there are cracks and bubbles in the steel pipe, they will be detected. After the quality inspection of steel pipes, strict manual selection is required. After quality inspection of steel pipes, paint is sprayed with numbers, specifications, production batches, etc. The crane is hoisted into the warehouse.