Sand casting greater cost. With a completed mold at the appropriate moisture content, the box containing the sand mold is then positioned for filling with molten metal—typically iron, steel, bronze, brass, aluminium, magnesium alloys, or various pot metal alloys, which often include lead, tin, and zinc. After being filled with liquid metal the box is set aside until the metal is sufficiently cool to be strong. The sand is then removed, revealing a rough casting that, in the case of iron or steel, may still be glowing red. In the case of metals that are significantly heavier than the casting sand, such
Metal and Machinery Workers Industrial Union Reuther Library in Detroit. Metal and Machinery Workers Industrial Union The Metal and Machinery Workers Industrial Union No. 440 (MMWIU) was a labor union in the United States which existed between 1907 and 1950. It organized workers in the manufacturing industry and was affiliated with the Industrial Workers of the World (IWW). The earliest recorded local of the MMWIU was in Bridgeport, Connecticut in 1907. A number of machinists' locals were also active under the IWW around that time, which dated from a period when a large number of craft union locals were switching their affiliation to the IWW, and