Two involute gears, the left driving the right: Blue arrows show the contact forces between them. The force line (or Line of Action) runs along a tangent common to both base circles. (In this situation, there is no force, and no contact needed, along the opposite common tangent not shown.) The involutes here are traced out in converse fashion: points (of contact) move along the stationary force-vector "string" as if it was being unwound from the left rotating base circle, and wound onto the right rotating base circle.

In manufacturing, mechanization replaced hand methods of making goods.

Prime movers are devices that convert thermal, potential or kinetic energy into mechanical work. Prime movers include internal combustion engines, combustion turbines (jet engines), water wheels and turbines, windmills and wind turbines and steam engines and turbines.

Powered transportation equipment such as locomotives, automobiles and trucks and airplanes, is a classification of machinery which includes sub classes by engine type, such as internal combustion, combustion turbine and steam.

Inside factories, warehouses, lumber yards and other manufacturing and distribution operations, material handling equipment replaced manual carrying or hand trucks and carts.

In mining and excavation, power shovels replaced picks and shovels. Rock and ore crushing had been done for centuries by water powered trip hammers, but trip hammers have been replaced by modern ore crushers and ball mills.

Bulk material handling systems and equipment are used for a variety of materials including coal, ores, grains, sand, gravel and wood products.

Construction equipment includes cranes, concrete mixers, concrete pumps, cherry pickers and an assortment of power tools.

Powered machinery

Powered machinery today usually means either by electric motor or internal combustion engine. Before the first decade of the 20th century powered usually meant by steam engine, water or wind.

Many of the early machines and machine tools were hand powered, but most changed over to water or steam power by the early 19th century.

Before electrification, mill and factory power was usually transmitted using a line shaft. Electrification allowed individual machines to each be powered by a separate motor in what is called unit drive. Unit drive allowed factories to be better arranged and allowed different machines to run at different speeds. Unit drive also allowed much higher speeds, which was especially important for machine tools.

A step beyond mechanization is automation. Early production machinery, such as the glass bottle blowing machine (ca. 1890s), required a lot of operator involvement. By the 1920s fully automatic machines, which required much less operator attention, were being used.

Military usage

The term is also used in the military to refer to the use of tracked armoured vehicles, particularly armoured personnel carriers, to move troops that would otherwise have marched or ridden trucks into combat. Mechanization dramatically improved the mobility and fighting capability of infantry. In the armed forces of industrialized countries, all infantry is typically mechanized, with the possible exception of airborne forces.

Mechanization may also refer in the broader military sense to "motorization" or the replacement of horses with motor vehicles for all functions, including logistics, artillery tractors, etc.