GALCCROSS34 Galvanized Cross, 3/4 Inch. A cross is a plumbing fitting that allows you to connect four sections of galvanized pipe. Each of the four connections has female threaded connections measuring at 3/4 inch. This fitting is specifically for use with 3/4 inch galvanized malleable iron pipe. Galvanized pipe and fittings are used in a variety of different plumbing applications. They can be used in hot water applications, but cold water applications are best with the galvanized fitting and piping construction. Its galvanized construction is very durable and its ability to resist corrosion and rust makes it a better choice over black iron or copper fittings. Even though the galvanized construction is extremely durable, they should not be used in underground applications.