Steel pipes are cylindrical tubes made from steel that are used many ways in manufacturing and infrastructure. They’re the most utilized product made by the the steel industry. The primary use of pipe is in the transport of liquid or gas underground—including oil, gas, and water. However, pipes of varying sizes are used throughout manufacturing and construction. A common household manufacturing example is the narrow steel pipe that runs the cooling system in fridges. Construction uses pipes for heating and plumbing. Structures can be built using steel pipe of varying sizes, such as handrails, bike racks, or pipe bollards.