The development of steel pipe production technology began with the rise of the bicycle manufacturing industry, the development of petroleum in the early 19th century, the manufacture of ships, boilers, and aircraft during the two world wars, the manufacture of thermal power boilers after the two wor

1. Small and medium-sized steel bars, wire rods, steel bars, medium-diameter steel pipes, steel wires and wire ropes, etc., can be stored in a well-ventilated material shed, but must be topped and bottomed.2. Some small steels, thin steel plates, steel strips, silicon steel sheets, small-diameter or