This minor group comprises machine operators and related workers in mineral and metal products processing and manufacturing, including machine operators, mineral and metal processing; foundry workers; glass forming and finishing machine operators and glass cutters; concrete, clay and stone forming operators; inspectors and testers, mineral and metal processing; metalworking and forging machine operators; machining tool operators; and machine operators of other metal products. They are employed by mineral ore and metal processing plants and cement processing plants; metal foundries and foundry departments of metal products manufacturing companies; glass and glass products manufacturing companies; concrete, clay and stone products manufacturing companies; sheet metal products manufacturing companies, sheet metal shops and other light metal products manufacturing establishments; structural steel fabrication, boiler and platework manufacturing companies and heavy machinery manufacturing companies; metal products and other manufacturing companies and machine shops; and in the shipbuilding, fabricated metal products, machinery and transportation equipment manufacturing industries.