Power tool

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A power tool is a tool powered by an electric motor, a compressed air motor, an internal combustion engine, direct burning of fuels and propellants, or even natural power sources like wind or moving water. Power tools are classified as either stationary or portable, where portable means handheld. They are used in industry, in construction, and around the house for driving, drilling, cutting, shaping, sanding, grinding, polishing, painting, and heating. Stationary power tools for metalworking are usually called machine tools. The term machine tool is not usually applied to stationary power tools for woodworking, although such usage is occasionally heard, and in some cases, such as drill presses and bench grinders, the exact same tool is used for both woodworking and metalworking.

Stationary power tools are prized not only for their speed, but for their accuracy. A table saw not only cuts faster than a hand saw, but the cuts are smoother, straighter and more square than even the most skilled man can do with a hand saw. Lathes produce truly round objects that cannot be made in any other way.

Common power tools include the drill, various types of saws, the router, the electric sander, and the lathe.

The term power tool is also used in a more general sense, meaning a technique for greatly simplifying a complex or difficult task.

History

The lathe is the oldest power tool, being known to the ancient Egyptians (albeit in a hand-powered form). Early industrial revolution-era factories had batteries of power tools driven by belts from overhead shafts. The prime power source was a water wheel or (later) a steam engine. The introduction of the electric motor (and electric distribution networks) in the 1880s made possible the self-powered stationary and portable tools we know today.

Energy sources

An electric motor is the universal choice to power stationary tools. Portable electric tools may be either corded or battery-powered. As of 2007, the limitations of battery life, battery recharge time, energy capacity, and cost keep the corded versions on the market. Compressed air is the customary power source for nailers and paint sprayers. A few tools (called powder-actuated tools) are powered by explosive cartridges. Tools that run on gasoline or gasoline-oil mixes are made for outdoor use; typical examples include most chainsaws and string trimmers. Other tools like blowtorches will burn their fuel externally to generate heat.

Safety

While power tools are extremely helpful, they also produce gratuitous amounts of noise and vibrations.[1] Using power tools without hearing protection over a long period of time can put a person at risk for hearing loss. The National Institute for Occupational Safety and Health (NIOSH) has recommended that a person should not be exposed to noise at or above 85 dB, for the sake of hearing loss prevention. [2] Most power tools, including drills, circular saws, belt sanders, and chainsaws, operate at sound levels above the 85 dB limit, some even reaching over 100 dB. [1] NIOSH strongly recommends wearing hearing protection while using these kinds of power tools. [3]

List of power tools

Power tools include:

See also

References

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External links

de:Elektrowerkzeug

hi:शक्तिचालित औजार ja:工具

pl:Elektronarzędzia
  1. 1.0 1.1 NIOSH Power tools database
  2. "Basis for the Exposure Standard", Criteria for a Recommended Standard: Occupational Noise Exposure Revised Criteria 1998, U.S. Department of Health and Human Services, 1998, pp. 24–5 
  3. Franks, John R., ed. (1996), "Appendix A: OSHA Noise Standard Compliance Checklist" (PDF), Preventing Occupational Hearing Loss: A Practical Guide, U.S. Department of Health and Human Services, p. 60