Stock Photo: Santa Monica, California: c. 1942. A Douglas Aircraft plant using extremely hard rubber as part of the dies to cut and form aluminum parts for airplanes for the World War II production effort. The rubber is compressed to the hardness of steel, and using the Guerin process, is forced into the dies to create the sheetmetal parts.

Stock Photo: 1035-12135 Santa Monica, California:  c. 1942. A Douglas Aircraft plant using extremely hard rubber as part of the dies to cut and form aluminum parts for airplanes for the World War II production effort. The rubber is compressed to the hardness of steel, and using the Guerin process, is forced into the dies to create the sheetmetal parts.