What Is Black Annealed Steel Pipe

Black stripped pipe is one of the most common steel pipes. If cold-rolled steel is heated to the annealing temperature, the surface color will turn black due to high temperature contact with air, which is called black stripped steel. Its surface has not been brightened, so it is black. The physical properties become soft, which is convenient for further welding to make steel pipes. The common hardness is 57HRB, and it can also be reduced to different hardness as needed.