Black Steel Pipe
Black steel is made of steel that has not been galvanized. Its name comes from the scaly, dark-colored iron oxide coating on its surface. Since it has a dark color surface that is form by iron oxide during the manufacturing process, it is called black steel pipe.

Black Iron Pipe
Most homes built before the 1960s have black iron pipe for things such as water and gas lines. It is a form of steel pipe, but made from more malleable products.
Blck Iron Pipe,It is actually a form of steel pipe, but it's made with a slightly different composition of materials to make it a little more malleable. However, water does corrode this type of pipe fairly easily in comparison to steel.

Black iron pipe VS black steel pipe

Construction is the main difference between the two products. Black iron pipes will have seams that allow the user to connect them easily to other pieces of pipe using connector valves. Steel pipe is more often used in industrial applications and it needs to be welded. 
Black iron pipe is used to transport natural and propane gas in residential applications. Black steel pipe is manufactured as seamless which makes it a better type for gas transportation and fire sprinkler systems since it can prevent fire better than galvanized pipe.

Texture
Steel pipe will have a very fine feel to it and almost be cool to the touch. It won't scratch as easily as black iron pipe, but that doesn't meant it can't be damaged by a wrench or hammer while working around it. Black iron pipe is course and grainy and will feel the same at room temperature. Black iron pipe will also flake if it is handled a lot. However, both can be heated very easily and will burn the user's hand.

Repairing
The main problem with black iron pipe--especially in the home--is leakage at connector spots. It requires a lot of work to fix these leaks, which is why many people no longer use black iron pipes. Steel pipes do not have that problem because it is most often welded. However, it is more expensive than black iron pipes or PVC.

Expenses
Steel pipe will usually cost about 20 percent more than black iron pipe, but it does a better job of saving resources in the long run by being more energy efficient. Its durability and cost are part of the reasons that use of steel pipes for large industrial jobs has grown in the United States. However, black iron pipe is more widely available than steel, which also makes it more convenient.