The uniform wall thickness of the DOM tubes with tighter outer and inner diameter tolerances results in maximum concentricity.
The heat treatment prior to cold drawing crystallizes the grain structure of the material and the weld seam, resulting in a homogeneous, controlled microstructure and hardness.
Cold drawing results in higher yield strength and tensile strength as well as better shaping of DOM pipes. A higher ductility is achieved by further heat treatment after cold drawing (delivery condition BK+S / stress-relieved annealed).
The surfaces of the outer and inner diameters are smoother, cleaner and denser than with other tube products. The heat treatment and the reduction of the tube cross-section during cold drawing level the weld seam and in most cases it can only be determined on the basis of the microsection.
DOM tubes can be produced within the dimensional program in an unlimited range of diameters and wall thicknesses given by changes in the mass of drawing rings and mandrels. This individual dimensional range provides the operator with material savings and lower costs by selecting a dimension that can match the mass of the finished product.
The narrow tolerances, controlled mechanical properties and smooth surface of DOM tubes lead to very good machining results and also allow further machining, such as hard chrome plating after appropriate pre-treatment.