Hercules offers premium Black fittings (black malleable iron fittings) are used to make connections to black iron pipe. Black iron pipe is used to transport natural and propane gas from the street or a tank to the home. Black iron pipe is also a popular choice in fire sprinkler systems due to its high heat resistance and for water supply lines due to its resistance to water damage. These fittings derive their name from the black oxide scale covering their surface.There are many different types of black fittings, each serving a particular function. 45 and 90 Degree Elbows are used to change the direction of the flow of water 45 or 90 degrees. These fittings are connected directly to a black pipe.45 and 90 Street Elbows are also used to change the direction of the flow of water 45 and 90 degrees. Unlike a standard elbow, a street elbow is connected to a black fitting.