A type of mechanical damagePhysical harm or degradation that occurs in a pipeline due to external forces, human activities, construction activities, or other mechanical actions. It can re… characterized by a groove, cut, or indentationA local change in pipe surface contour caused by an external force such as mechanical impact or rock impingement but is not accompanied by loss of metal. on the surface of the pipe. It typically occurs when a sharp object, such as a rock, tool, or equipment, comes in contact with the pipeline and causes material removal or displacement.