California: machine parts are made by different methods of heavy machinery milling. New process of chemical milling is showcased at Manhattan Beach’s California Plant of the United States Chemical Milling Corporation. The new process is used in supersonic aircraft construction. Women work on a template for duct work. Areas peeled away to prepare for milling. Women working on the works shop floor. Templates lowered into large chemical baths outside, by a crane. Man squirts oil onto metal sheets so they can be tested for. Views of different read outs. Jet plane takes off from air field.