The US Department of Defense initiated the Heavy Press Program in the 1950s to build large forging and extrusion presses for manufacturing aircraft parts. The program was a response to the need for lighter and stronger parts for supersonic aircraft, and it led to significant advancements in metal processing and aircraft manufacturing. The presses were used to produce parts for various applications, including military aircraft, spacecraft, and commercial jets. The program is considered a classic example of military technological spillovers, with benefits extending beyond the original purpose to other industries.