DOM tube is made from strip, then welded and finally drawn over a mandrel and often through a die to smooth out the weld seam and precisely size the OD and ID. Close tolerance diameters or tube with a very heavy wall for the required diameter may be Drawn Over a Mandrel (DOM).
Tube can be rolled up from flat strip and welded or extruded. Tube material (steel, stainless steel, aluminum, other) must be defined as well as the preferred manufacturing process. Tubes are defined by Tube OD and Tube Wall thickness while pipe is defined by ID and a scheduled gauge of wall thickness. This can be done in several ways but using a consistent drawing standard will benefit your suppliers and insure you receive consistent quality. The initial step in determining a tube bending process is to define the part. Mandrel bending is a special application of rotary draw bending when bends have a small radius or maximum tube roundness must be maintained in the bend. The different tube bending processes are rotary draw bending, crush bending, and roll bending. Each process has its own strengths and economics that must be considered. A knowledge of the various tube bending methods, including capabilities, limitations, and economics will help you determine the most economical process for a quality product at the best value.
