Stamping vs. Hydroforming

Stampings have been the primary way to manufacture Body-in-White (BIW) parts since the early days of the automobile. Stamping allows the design flexibility to create simple or complex parts using a well-understood technology with an established manufacturing base. Using stampings, a BIW engineer must provide for a number of design criteria; including attachment features such as holes and slots, formations to clear adjacent components and manufacturing feasibility for the specified material. Balancing these criteria can sometimes compromise the most important function of the stamping; its structural capability.

In addition, with increasing impact requirements and safety regulations, these structures now demand higher performance.

BIW engineers are very familiar with designing for stamped parts, so it is common practice to balance the packaging needs with new structural requirements by simply increasing the gage and grade of the stampings.

Also, since stampings have been the mainstay of BIW construction, most body shops are set up to accommodate them. Well established spot welding lines are in place to bring these stampings together to form the body.

So, if an engineer can alter gage and grade to meet changes in performance, utilize a welding method that has been in place for decades, why go to any other method to manufacture these parts? Two words; structural efficiency.

Thicker and stronger stamped designs may meet the new structure and packaging needs, but typically at a mass penalty.

In this study we will take a look at why hydroform tubes are structurally more efficient than stampings, elaborate on the findings from HIBS I and lastly look at real world applications that recognize the efficiency of hydroform tubes.