A power tool is the kind of a tool which is activated or brought to function by means of an additional source of power. Usually the tools which are used by applying the manual labor are called as hand tools or manual tools. On the other this specific kind of tools is that which is powered by an additional source which is electric power in many cases. There are different types of the tools operated by external sources of power. The most common of these tools is the electric motor. Other than application of electricity as an external source of power, the energy by means of combustion engines is also used in some tools and machines.
There are many other sources of power used in the power tool devices. Sometimes an indirect source of energy is used while at other times, direct energy source is used. For example in some cases the devices and machines are run by means of the direct energy which is coming from the burning of fuels and other propellants. Similarly there are many other devices which make use of the energy coming from steam engines. This energy is used to ruin the machines and devices and it is far greater in value and efficiency as compared to the hand driven tools and machines. Sometimes natural and renewable sources of energy are also used in driving many different kinds of power tool devices and machines. These include the harnessing and using the energy stored in wind and moving water. This energy is used in running the tools, machines and whole set up like the power generators and windmills. There are different applications and uses of these tools driven by external sources of power and energy. Most commonly these tools find their applications in the field of industry and construction.
In addition to their usage in the fields of industry and construction, these power tool devices are also used in many other fields. Usually these tools are employed in construction around the houses. These tools are employed for the purposes of driving, cutting, drilling, shaping, polishing, painting, heating, sanding and several other construction related activities. Depending upon their functions, sizes and mobility, these tools are divided into two major categories. On kind of the power tool devices is that which is portable. These devices and tools can be held in hands and can be taken from one place to another. Another kind is of the stationary tools. These tools are not movable and all the work required to be done is brought to their places. Both these kinds of devices have their own advantages. Although the portable devices are helpful in being mobile, but there is often a compromise made on their speed and efficiency. On the other hand the stationary devices have comparatively greater speed, accuracy and efficiency.
The specific kinds of power tool devices which are used in metal works are called as the machine tools. These tools are not meant for wood working. However there are some machines and tools which are used for both the wood and metal workings.