SIC 3566 Speed Changers, Industrial High-Speed Drives, and Gears

SIC 3566

Firms in this industry manufacture speed changers, industrial high-speed drives, and gears. Hydrostatic drives are classified under SIC 3594: Fluid Power Pumps and Motors; automatic transmissions are in SIC 3714: Motor Vehicle Parts and Accessories; and aircraft power-transmission devices are found in SIC 3728: Aircraft Parts and Auxiliary Equipment, Not Elsewhere Classified.

NAICS CODE(S)

333612

Speed Changers, Industrial High-Speed Drive, and Gear Manufacturing

INDUSTRY SNAPSHOT

The industry provides basic mechanical power transmission components used in most industrial machinery. It demonstrated slow but steady growth throughout the late 1990s, with the value of shipments increasing from $2.39 billion in 1997 to $2.47 billion in 2000. Companies in this industry downsized during the late 1990s; the total number of employees decreased from 16,182 in 1997 to 15,477 in 2000. Over the same time period, the number of production workers fell from 11,231 to 10,944. Over a quarter of the industry's shipments were generated by only four establishments. Trends affecting this industry during the late 1990s included automation production technology and government restrictions on industrial waste.

BACKGROUND AND DEVELOPMENT

Typical manufacturing includes metal grinding, cutting, degreasing, and surface finishing (including hardening). Such metalworking includes basic metal-shaping, heat treatment, and metallurgic modifications using chemicals during processing.

The origin of the gear concept remains uncertain. It was not one of the basic five "simple machines" defined by Hero of Alexandria (the wheel and axle, the lever, the pulley, the wedge, and the screw), but it probably evolved from the screw. Until the Industrial Revolution, craftsmen used the gear primarily in small mechanisms like clocks, or to guide and locate machinery components. The idea of using it to transmit power in larger machines did not gain prevalence until the 19th century in England.

In America, the technology and the expertise of local artisans to produce quality gears lagged behind Europe until near the end of that century. In 1896, F.W. Fellows patented a gear-shaping machine that could turn out a wide variety of gears quickly and cheaply. The rise of the "American system" of mass manufacturing on an...