Making steel components
- Molten steel is made by melting iron ore and coke (a carbon-rich substance that results when coal is heated in the absence of air) in a furnace, then removing most of the carbon by blasting oxygen into the liquid. The molten steel is then poured into large, thick-walled iron molds, where it cools into ingots.
- In order to form flat products such as plates and sheets, or long products such as bars and rods, ingots are shaped between large rollers under enormous pressure. Hollow tubes, such as those used to form the latticed booms of large cranes, may be made by bending sheets of steel and welding the long sides together. They may also be made by piercing steel rods with a rotating steel cone.
- The cables used to lift weights are made from steel wires. To make wire, steel is first rolled into a long rod. The rod is then drawn through a series of dies which reduce its diameter to the desired size. Several wires are then twisted together to form cable.
