 Steel pipe is often joined with threaded connections; tapered threads are cut into the end of the pipe, sealant is applied in the form of thread-sealing compound or thread seal tape (also known as PTFE or Teflon tape) and the pipe is threaded into a threaded fitting with a pipe wrench.Threaded steel pipe is widely used in buildings to convey natural gas or propane fuel, and is a popular choice in fire sprinkler systems due to its resistance to mechanical damage and high heat.Threaded steel pipe may still be used in high-security locations, because it is more resistant to vandalism, more difficult to remove, and its scrap value is lower than copper or brass.