Black pipe is a type of ordinary steel pipe.

Cold-rolled steel becomes black when heated to the annealing temperature, as the surface turns black due to contact with air at high temperatures. This is known as black annealed steel. Its surface has not been brightened, hence the black color. The physical properties become softer, making it easier to weld and form into steel pipes. The common hardness is 57HRB, and it can be annealed to different hardnesses as required.