Video: How Forged Pistons are Made

Mahle pistonsAs we keep saying here at Mac’s Motor City Garage, we appreciate clear, simple, and accurate technical info. This great little five-minute video shows how forged pistons are manufactured. Solid material, check it out.   -Photo courtesy Mahle GmbH 

 

 

It’s true: Modern automobiles employ some of the most advanced technology devised by man. But that said, there’s nothing about the basic engineering that any automotive enthusiast can’t understand and enjoy. Take pistons, for instance—the heart of an engine.

This great little video, courtesy of the How It’s Made series, breaks down the manufacture of a forged piston into its essential steps. First, blanks are cut to length from aluminum alloy round stock. The blanks are then heated to 800°F and forged in a die under 2000 tons of hydraulic pressure. This critical stage gives the piston its basic shape and also imparts a directional grain structure to the metal to increase its strength.

From there, two successive heat treating stages first strengthen and next normalize and stress-relieve the part. Then the piston is treated to its comprehensive machining process, including turning, drilling, boring, and milling, followed by a hand deburring and inspection stage and a cleaning in deionized water. While forged aluminum pistons can be used in anything from leaf blowers to construction equipment to Top Fuel Dragsters, the manufacturing process is surprisingly similar. Video below.