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How do presses shape metal and plastic parts?

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A diagram displays six types of simple machines with labeled illustrations: inclined plane, wedge, screw, lever, wheel and axle, and pulley, each shown with real-world examples like ramps, axes, screws, seesaws, door handles, and pulleys lifting objects. — machine Six simple machines for transforming energy into work.

Presses shape metal and plastic parts using distinct mechanical processes, primarily relying on the use of dies or molds to achieve desired configurations.12

Metal Shaping

Metal parts are typically formed using presses equipped with a movable ram and a fixed bed. A punch mounted on the ram descends into a matching die, exerting force to cut, bend, or shape sheet metal. Forging presses use dies with specific cavities to shape white-hot metal blanks. These machines may be powered by mechanical, hydraulic, or pneumatic systems. Depending on the temperature during deformation, the process is categorized as hot working—which allows for significant strain—or cold working, which increases the hardness and strength of the metal.1234

Plastic Shaping

Unlike metal stamping, which relies on high force to deform material, plastic shaping typically involves molding. In injection molding, a machine melts resin and uses a screw-driven ram to force the molten material into a cooled mold. Once the plastic solidifies within the cavity, the mold opens and the part is ejected.25