Editing Angle grinder

{{Short description|Handheld power tool for cutting or polishing}}
[[Image:AngleGrinder.jpg|thumb|Angle grinder]]

An '''angle grinder''', also known as a '''side grinder''' or '''disc grinder''', is a handheld [[power tool]] used for [[grinding (abrasive cutting)]] and [[polishing]].

== History ==

The high-speed angle grinder was invented in 1954<ref>[https://www.flex-tools.com/en/company/history/ History]</ref> by German company Ackermann + Schmitt ([[Flex-Elektrowerkzeuge|FLEX-Elektrowerkzeuge GmbH]]) in [[Steinheim an der Murr]].<ref>{{Citation |last=Henke |first=Michael |date=January 2009 |title= ''Nachgefragt: Warum heißen Winkelschleifer "Flex"''| publisher=Verlagsgesellschaft Rudolf Müller | magazine =Fliesen und Platten |publication-place= Köln| page=45 |url=http://www.flex-tools.com/documentpool/Winkelschleifer-FLEX-PR-FLiesen-Platten.pdf |archive-url=https://web.archive.org/web/20160304073121/http://www.flex-tools.com/documentpool/Winkelschleifer-FLEX-PR-FLiesen-Platten.pdf |access-date= 2014-01-16 |archive-date= 2016-03-04}}</ref>

== Naming ==

In German, Dutch, Slovak, Czech, Polish, Croatian, Romanian, Hungarian, Bulgarian and Latvian, an angle grinder is colloquially called a "flex", and in Italy and in Spanish-speaking countries it is sometimes called "flexible". In [[Switzerland]] it is known as "Perles" from a popular brand of cutting tools. In Polish it is also known as "kątówka"<ref>{{Cite web|url=http://www.technikanarzedziowa.pl/2014/11/08/podaj-flexa-krotka-historia-szlifierki-katowej/|title = 'Podaj flexa!' – krótka historia szlifierki kątowej}}</ref> or "gumówka"<ref>[https://pl.wiktionary.org/wiki/szlifierka_kątowa Wikidictionary]</ref> (= the rubber thing), which refers to the elasticity of certain types of disks. However they are never made out of true rubber due to fire hazard. In Russian, it is known as "болгарка" ("bolgarka")<ref>{{Cite web|url=https://www.webmiastoto.com/?p=27184|title=Защо ъглошлайфът в Русия се нарича "българка"?|date=11 July 2023 }}</ref> (literally "Bulgarian" of the feminine gender), since the first angle grinders in the USSR were Bulgarian made.<ref>{{Cite web|url=https://gp.by/novosti/kaleidoscope/news142402.html|title = 'Болгарка' - история названия и секреты правильного выбора инструмента}}</ref>

== Design ==

Angle grinders can be powered by an [[electric motor]] or [[compressed air]]. The motor drives a geared head at a right-angle, on which can be mounted an [[abrasive]] [[grinding wheel|disc]] or a thinner cut-off disc, either of which can be replaced when worn. Angle grinders typically have an adjustable guard and a side-handle for two-handed operation. Certain angle grinders, depending on their speed range, can be used as [[sander]]s, employing a sanding disc with a backing pad or disc. The backing system is typically made of hard plastic, phenolic resin, or medium-hard rubber, depending on the amount of flexibility desired.

== Uses ==

Although developed originally as tools for rigid abrasive discs, the availability of an interchangeable power source has encouraged their use with a wide variety of cutters and attachments.

Angle grinders are used in [[metal fabrication|metal fabrication shops]] and on [[construction]] sites.{{cn|date=May 2024}} They are also common in [[machine shop]]s, along with [[die grinder]]s and [[bench grinder]]s.{{cn|date=May 2024}}

Angle grinders may be used for removing excess material from a piece. There are many different kinds of discs that are used for various tasks, such as cut-off discs ([[diamond blade]]), abrasive grinding discs, grinding stones, sanding discs, [[wire brush]] wheels and polishing pads.{{cn|date=May 2024}} The angle grinder has large [[bearing (mechanical)|bearings]] to counter side forces generated during cutting, unlike a power [[drill]], in which the force is axial.

Angle grinders are widely used in [[metalworking]] and [[construction]], emergency rescues, and even for the theft of bicycles. Generally, they are found in workshops, service garages and auto body repair shops. There are a large variety of angle grinders with different disc sizes and power sources: [[cordless|battery]], [[power cord|corded]] or [[pneumatics|pneumatic]]. Other variables include the power of the motor, [[revolutions per minute|rpm]], and [[mandrel|arbor]] size. Generally, disc size and power increase together. Disc size is usually measured in inches or millimeters. Common disc sizes for angle grinders in the United States include 4, 4.5, 5, 6, 7, 9 and 12&nbsp;inches, with the most popular sizes being the 4.5 and 5" size. In Europe, the most common sizes for angle grinder discs are 115 and 125 millimeters.

Discs for pneumatic grinders are much smaller. Pneumatic grinders are generally used for lighter-duty jobs in which more [[accuracy and precision|precision]] is required. That is because pneumatic grinders can be powerful while being small and light, because they do not contain heavy copper motor windings. It is harder for an electric grinder to maintain adequate power with smaller size. Electric grinders are more commonly used for larger, heavy duty jobs. However, there are also small electric grinders and large pneumatic grinders.

Angle grinders have been used to remove [[wheel clamp]]s from vehicles.<ref>{{cite web |title='Superhero' takes on clampers |url=http://news.bbc.co.uk/1/hi/england/3112670.stm |website=[[BBC News]] |date=2003-09-16 |archive-url=https://web.archive.org/web/20230304014652/http://news.bbc.co.uk/1/hi/england/3112670.stm |archive-date=2023-03-04 |url-status=live}}</ref><ref>{{cite web |title=WATCH: Man takes angle grinder to clamp in Limerick |url=https://www.newstalk.com/news/watch-man-takes-angle-grinder-to-clamp-in-limerick-632007 |website=[[Newstalk]] |date=2015-10-31 |archive-url=https://web.archive.org/web/20230304015016/https://www.newstalk.com/news/watch-man-takes-angle-grinder-to-clamp-in-limerick-632007 |archive-date=2023-03-04 |url-status=live}}</ref>

== Safety and health ==
{{Main|Particulates#Health_effects}} {{seealso|Power_tool#Health_impact|Brain health and pollution}}
{{expand section|date=April 2024}}
[[File:Angle Grinder cutting a steel chain - Video.webm|thumb|thumbtime=0:09|upright|Video: An angle grinder is used for cutting through a steel chain, kept under tension by a second person to avoid impeding the wheel of the grinder. Large amounts of [[Particulates#Health_effects|potentially harmful particulates]] (metal dust) are being generated.)]]
[[File:Mechanical arm effects on portable grinder vibrations.webm|thumb|A video on vibration research done on pneumatic grinders]]

Use of angle grinder can emit a large amount of small respirable dust.<ref name=":0">{{Cite journal |last=Chen |first=Jihe |last2=Shi |first2=Xunxian |last3=Liu |first3=Shuo |last4=Wang |first4=Ming |last5=Wang |first5=Pei |last6=Jiang |first6=Zhongan |date=2023-11-01 |title=Performance optimization and experimental analysis of angle grinder with dust collection hood |url=https://www.sciencedirect.com/science/article/abs/pii/S0957582023008157 |journal=Process Safety and Environmental Protection |volume=179 |pages=228–240 |doi=10.1016/j.psep.2023.09.004 |issn=0957-5820|url-access=subscription }}</ref><ref>{{Cite journal |last=Healy |first=Catherine B. |last2=Coggins |first2=Marie A. |last3=Van Tongeren |first3=Martie |last4=MacCalman |first4=Laura |last5=McGowan |first5=Padraic |date=2014-11-01 |title=An Evaluation of On-Tool Shrouds for Controlling Respirable Crystalline Silica in Restoration Stone Work |url=https://academic.oup.com/annweh/article-abstract/58/9/1155/244914 |journal=The Annals of Occupational Hygiene |volume=58 |issue=9 |pages=1155–1167 |doi=10.1093/annhyg/meu069 |issn=0003-4878|url-access=subscription }}</ref><ref>{{Cite journal |last=Weller |first=Michael |last2=Clemence |first2=Dennis |last3=Lau |first3=Abe |last4=Rawlings |first4=Mark |last5=Robertson |first5=Amy |last6=Sankaran |first6=Bhoopathy |date=2024-03-01 |title=An assessment of worker exposure to respirable dust and crystalline silica in workshops fabricating engineered stone |url=https://academic.oup.com/annweh/article/68/2/170/7473352 |journal=Annals of Work Exposures and Health |volume=68 |issue=2 |pages=170–179 |doi=10.1093/annweh/wxad072 |issn=2398-7308|url-access=subscription }}</ref> Excessive dust emission is regulated by air pollution laws and violation can result in fines. Proper use of well-designed [[Dust collector|dust collectors]] (e.g. [[Dust collection hood|dust collection hoods]]) can reduce dust concentration significantly (up to 80-90%).<ref name=":0" /> 

The disc type (fibre disc or grinding wheel) affects the dust's size distribution. The dust emitted can be as small as PM1.<ref>{{Cite web |title=Comparison of dust emissions when using various 3M fibre discs and grinding wheels |url=https://multimedia.3m.com/mws/media/1379719O/vito-report-dust-emissions-cubitron-ii-fibre-dcgw-en-version.pdf}}</ref>

The use of an angle grinder in cutting is not preferred, because large amounts of harmful sparks, fumes and [[particulates]] are generated when compared with using [[reciprocating saw]] or [[band saw]].<ref>{{cite web | url=https://www.youtube.com/watch?v=XMXa1QImM54 | title=What's the Best Way to Cut Thick Steel?| website=[[YouTube]]| date=7 August 2021}}</ref> Angle grinders produce [[sparks (fire)|sparks]] when cutting ferrous metals. They also produce [[sherd|shards]] when cutting other materials. The blades themselves may break, which is a hazard to the face and eyes especially, as well as other parts of the body. Consequently, a full face shield and other protective clothing must be worn. Angle grinders should never be used without their guard or handle attached. All [[workpiece]]s should be securely clamped or held firmly in a vise.<ref>[https://www.safework.sa.gov.au/workplaces/plant-tools-and-vehicles/angle-grinders Risk Control]</ref> In a sound pressure level and vibration study conducted by the US [[National Institute for Occupational Safety and Health]], grinders under an unloaded condition created noise which ranged from 91 to 103 [[A-weighting|dBA]].<ref name="multiples">National Institute for Occupational Safety and Health (NIOSH) Division of Applied Research and Technology (DART), ''Hand-held Power Tools Sound Pressure and Vibrations Database'', 2009</ref>

== See also ==

* [[Abrasive saw]]
* [[Health impacts of sawdust]]

== References ==

{{refs}}

== External links ==
{{commonscat|Angle grinders}}

* [https://www.safework.sa.gov.au/workplaces/plant-tools-and-vehicles/angle-grinders Angle grinders Safework SA]

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[[Category:1954 establishments in West Germany]]
[[Category:1954 in science]]
[[Category:Articles containing video clips]]
[[Category:German inventions]]
[[Category:Grinding machines]]
[[Category:Hand-held power tools]]

[[it:Smerigliatrice#Smerigliatrice angolare]]