Types of Metal Forming: What You Need to Know about Pressing, Forging, Hydroforming and FluidForming

 In Hydroforming, Metal Forming, Technology

Metal forming is the general term for a variety of different manufacturing processes that deform metal into a desired shape or geometry. In order for metal to be formed (or deformed) into a particular shape, an external force must be applied the material that exceeds the original strength of the metal sheet or tube that is being formed.

Sheet metal forming is one of the most critically important technologies in the manufacturing industry. Although metal forming contributes significantly to the health of our economy until very recently, few significant advancements had been made since the Industrial Revolution. In this post, we’ll discuss legacy methods such as die stamping, forging, traditional hydroforming, and FluidForming.

Die Stamping and Pressing

Die stamping, also referred to as “pressing,” is one of the oldest forms of metal stamping. During this process a flat piece of sheet metal is placed into a press where a tool and die surface pushes the metal into a desired shape. In some instances, the metal must go through several different stages of pressing which may damage the surface of the material and weaken the metal.

Operating costs, equipment costs, and tooling and die costs, and post production fixturing can be prohibitive.


Forging is the oldest known metal working process and is often classified according to the temperature (cold, warm, or hot working)  at which the metal is formed. Forging produces strong pieces, however, capital expenditures and its impact on the environment are significant.

20th Century Hydroforming

Hydroforming is a cost-effective way of shaping conventional ductile metals such as aluminum, brass, steel, and stainless steel as well as today’s more sophisticated alloys into lightweight, structurally stiff, and strong pieces. The automotive, aerospace, medical, and appliance industries frequently turn to hydroforming to create strong, complex shapes.

Multiple variations of the first version of sheet metal hydroforming (which was patented in 1955) exist today. Typically, these legacy methods operate with forming pressures in the range of 70-100 mPA/10,000-15,000. Forming of sheet metal is traditionally achieved by pressurizing a flexible bladder filled with hydraulic oil. This bladder expands against the sheet metal and deforms it into the mold.

FluidForming: Hydroforming for the 21st Century

The FluidForming technology, which is a modern reinvention of hydroforming, was first patented in Germany and was developed to fill the market gap for a higher quality, more accurate, faster, intrinsically repeatable, and affordable metal forming process.

What is FluidForming? This modern, bladder-free take on traditional hydroforming utilizes water at pressures up to 400 mPA/60,000 psi. FluidForming and achieves a greater degree of detail, strength, and repeatability than any existing legacy method. Springback and warping are also minimal. Finally, because water comes into contact with just one side of the metal surface, it’s the perfect metal forming process for pre-finished metals and high-tech alloys.

The technology’s inventor, Reinhold Wesselmann, developed the FluidForming technology and process to address current trends in the metalworking industry such as sustainability, additive manufacturing, rapid prototyping, cost reduction, and the need for highly accurate, precision-driven components.

Learn more about metal forming and find out if the FluidForming hydroforming technology is right for your next project. Contact FluidForming Americas today at (800) 497-3545 or email us at info@ffamericas.com.

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