Carbon Steel Butt Weld Fittings MSS SP 75 WPHY 70 are commonly utilised for applications that do not necessitate corrosion-resistant materials such as stainless steel and nickel alloys. When exposed to water, carbon steel items corrode and rust quickly. Carbon steel pipe is utilised for both above- and belowground liquid, gas, and steam services. It should not be used in corrosive services, although it can be used in caustic ones. They also have a higher tensile strength.