As the largest piston manufacturer worldwide, our portfolio includes a variety of product and material choices: cast or electron-beam-welded aluminum pistons and composite pistons with aluminum, nodular cast iron, and steel skirts. Composite pistons are screwed to piston crowns made of forged steel—a material with an excellent track record. Steel pistons are available not only with a screwed connection but also in friction-welded or high-temperature brazed variants.