Official definition
This subsector comprises establishments primarily engaged in manufacturing industrial and commercial machinery. These establishments assemble parts into components, subassemblies and complete machines. They may make the parts themselves, using general metal-working processes, or purchase them. Establishments tend to specialize in producing machinery designed for particular applications, and this is reflected in the structure of the industry groups and industries. A broad distinction exists between general-purpose machinery, that is designed to be used in a variety of industrial applications, such as pumping or machining, and special-purpose machinery, that is designed to be used in a particular industry, such as agriculture or printing. The first three industry groups consist of establishments that produce special-purpose machinery. Establishments that produce general-purpose machinery are classified in the remaining industry groups. Establishments primarily engaged in rebuilding machinery are included in the same industry as establishments manufacturing the particular type of new machinery. Unless otherwise specified, establishments primarily engaged in manufacturing parts, designed for use solely or principally with a particular machine, are classified in the same industry as establishments manufacturing that type of machinery.