In the metal forming industry ‘hydroforming’ has become somewhat of a buzzword and general term for metal shaping. But there are many ways of shaping metal in this industry, all with their own unique advantages.
Deep draw hydroforming is a process by witch metal sheets (commonly referred to as ‘blanks’) are formed into parts by being drawn through a die by a punch. The edges of the blank are held in place by clamps called ‘blank holders’ while the punch pushes the metal sheet into an opening to shape it. The punched piece can also be put through the process again to ultimately increase the height and reduce the diameter of the punched item. This second pass is usually known as a redraw. Draws can be done multiple times until the desired height and diameter are reached.
Approximately 40% of the blank diameter can be drawn in one pass, with one set of tools. To continue increasing height and decreasing diameter, multiple draws must be done to avoid punching through the bottom of the blank. Of course, percentages will vary depending on type of metal, blank thickness, quality of materials, and what shape the final item is being formed into.
As previously mentioned, different types of metal stand up to being drawn better than others. One of the best for this process is aluminum. It is strong yet lightweight, easily drawn, readily accepts a host of finishes, has a pleasing appearance, and can be shipped without worry that it will rust. On top of all that, tooling aluminum is cheaper than generally any other metal. Other good metals for this type of tooling include copper, stainless steel, and brass.
For more information on hydroforming and metal shaping in general, feel free to contact us.