Angle grinder

Short description: Handheld power tool for cutting or polishing

Angle grinder

An angle grinder, also known as a side grinder or disc grinder, is a handheld power tool used for grinding (abrasive cutting), polishing, sanding, and similar applications. Its use is especially prevalent in metalwork.

## Contents

* 1 History
* 2 Naming
* 3 Design
* 4 Uses
* 5 Safety and health
* 6 Gallery
* 7 See also
* 8 References
* 9 External links

## History

The high-speed angle grinder was invented in 1954[1] by German company Ackermann + Schmitt (FLEX-Elektrowerkzeuge GmbH) in Steinheim an der Murr.[2] Before the high speed angle grinder of 1954, many other inventors from the early 20th century had produced grinders and similar cutting tools for use in metalwork. As electric power tools became more available and affordable, the prevalence of angle grinders in workshops increased, and they also became a popular DIY tool, especially after the invention of battery-powered cordless angle grinders.[3]

## 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". This originates with Ackermann + Schmitt's use of a flexibile shaft between the motor drive and the tool.[4] The name "flex" proved so enduring that Ackermann + Schmitt changed their company's name to FLEX.

In Switzerland it is known as "Perles" from a popular brand of cutting tools. In Finnish, angle grinders are colloquially known as "rälläkkä", an onomatopoeia for the distinctive sound they make when cutting (the Estonian name "relakas" comes from the Finnish name). In Polish it is also known as "kątówka"[5] or "gumówka"[6] (literally "rubber thing"), which refers to the elasticity of certain types of disks (however these are never made out of true rubber due to fire hazard). In Russian, the tool is known as "болгарка" ("bolgarka")[7] (literally "Bulgarian" of the feminine gender), since the first angle grinders in the USSR were Bulgarian-made.[8]

Angle grinders are sometimes confused with cut-off saws, though these have less variable applications.

## 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 is a spindle for mounting discs. The nature of these discs varies based on their intended use. Abrasive disc or thinner cut-off discs are the most common, and both can be replaced when worn. Angle grinders typically have an adjustable guard and a side-handle for two-handed operation. Many modern brands of angle grinders have a two-stage constant pressure trigger switch (also known as a "deadman's switch") to prevent the user accidentally switching the tool on, especially when changing discs.

Depending on their speed range, angle grinders can be used as sanders, 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. Wheels are most often added or removed using an angle grinder wrench, a distinctive two-pin spanner used to attach discs to the grinder's spindle.

## 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 shops, on construction sites[9] and in machine shops, along with die grinders and bench grinders. There are different discs for different tasks, cut-off discs (diamond blade), abrasive grinding discs, grinding stones, sanding discs, wire brush wheels and polishing pads. Typically, cut-off discs are disposable and will be discarded once they are worn down. Angle grinders have large bearings to counter the side forces generated, unlike a power drill, where the force is axial. This versatility give angle grinders a wide variety of uses, including cutting, sanding, grinding, demolition, polishing, and stripping. Though they can be used on other materials, they are predominantly used on metal and masonry.

Angle grinders are widely used in metalworking, construction, emergency rescue, and the theft of bicycles, and can be 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: battery, corded or pneumatic. Other variables include the motor power and speed, rpm, and arbor size. Generally, disc size and power increase together. Disc size is usually measured in inches or millimetres. Common disc sizes for angle grinders in the United States include 4, 4.5, 5, 6, 7, 9 and 12 inches, with the most popular sizes being the 4.5 and 5" size. Outside North America, the most common sizes for angle grinder discs are 115 and 125 millimetres.

Discs for pneumatic grinders are much smaller, and pneumatic grinders tend to be used for lighter-duty jobs in which more precision is required. This 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 also been used to remove wheel clamps from vehicles.[10][11]

## Safety and health

Main article: Particulates § Health_effects

See also: Power_tool § Health_impact, and Brain health and pollution

File:Angle Grinder cutting a steel chain - Video.webm File:Mechanical arm effects on portable grinder vibrations.webm

Use of angle grinder can emit a large amount of small respirable dust.[12][13][14] Excessive dust emission is regulated by air pollution laws and violation can result in fines. Proper use of well-designed dust collectors (e.g. dust collection hoods) can reduce dust concentration significantly (up to 80-90%).[12]

The disc type (fibre disc or grinding wheel) affects the dust's size distribution. The dust emitted can be as small as PM1.[15]

Angle grinders can produce considerable volumes of harmful sparks, fumes and particulates, especially when compared to using a reciprocating saw or band saw.[16] Angle grinders produce sparks when cutting ferrous metals, and can also produce 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 - in these instances debris moving at high speed may cause penetrating injuries.[17]

A grinder disc becoming lodged or jammed can cause kickback, a dangerous phenomenon where the tool will jump or thrust back towards the user. Consequently, a full face shield and other protective clothing such as cut resistant gloves must be worn at all times. Cutting discs often have arrows or marking specifying which direction they should be used in, and it is recommended to adjust the guard so sparks fly away from the angle grinder operator. Sparks can also make angle grinders a fire hazard, especially in enclosed spaces.

Angle grinders should never be used without their guard attached and the handle should only be removed if absolutely necessary. All workpieces should be securely clamped or held firmly in a vise.[18] 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 dBA.[19]

## Gallery

* Cut-off wheel

* Grinding wheel for grinding

* Diamond disc or diamond cutting wheel, for cutting stones like granite

* Concrete grinding wheel, to remove concrete from surface or polish concrete entirely

* Diamond grinding disc for flat surfacing of stonework

*   * Flap disk. It is rough and made of sandpaper for sanding surfaces such as iron and wood

* Flapwheel for cleaning, polishing, grinding, and deburring

## See also

* Disc cutter
* Abrasive saw
* Sander
* Health impacts of sawdust
* Diamond grinding cup wheel
* Flapwheel

## References

1. ↑ History
2. ↑ Henke, Michael (January 2009), "Nachgefragt: Warum heißen Winkelschleifer "Flex"", Fliesen und Platten (Köln: Verlagsgesellschaft Rudolf Müller): 45, http://www.flex-tools.com/documentpool/Winkelschleifer-FLEX-PR-FLiesen-Platten.pdf, retrieved 2014-01-16
3. ↑ "Power Tools History: The Angle Grinder From Past To Present". https://www.kynko.com.cn/blog/power-tools-history-the-angle-grinder-from-past-to-present_b24.
4. ↑ "70 years angle grinder - FLEX". https://www.flex-tools.com/en/company/70-years-angle-grinder.
5. ↑ "'Podaj flexa!' – krótka historia szlifierki kątowej". http://www.technikanarzedziowa.pl/2014/11/08/podaj-flexa-krotka-historia-szlifierki-katowej/.
6. ↑ Wikidictionary
7. ↑ "Защо ъглошлайфът в Русия се нарича "българка"?". 11 July 2023. https://www.webmiastoto.com/?p=27184.
8. ↑ "'Болгарка' - история названия и секреты правильного выбора инструмента". https://gp.by/novosti/kaleidoscope/news142402.html.
9. ↑ "Angle Grinder Toolbox Talk". Cornell University Environment, Health and Safety. https://ehs.cornell.edu/campus-health-safety/occupational-safety/tool-and-machine-safety/angle-grinder-toolbox-talk.
10. ↑ "'Superhero' takes on clampers". 2003-09-16. https://news.bbc.co.uk/1/hi/england/3112670.stm.
11. ↑ "WATCH: Man takes angle grinder to clamp in Limerick". 2015-10-31. https://www.newstalk.com/news/watch-man-takes-angle-grinder-to-clamp-in-limerick-632007.
12. ↑ 12.0 12.1 Chen, Jihe; Shi, Xunxian; Liu, Shuo; Wang, Ming; Wang, Pei; Jiang, Zhongan (2023-11-01). "Performance optimization and experimental analysis of angle grinder with dust collection hood". Process Safety and Environmental Protection 179: 228–240. doi:10.1016/j.psep.2023.09.004. ISSN 0957-5820. https://www.sciencedirect.com/science/article/abs/pii/S0957582023008157.
13. ↑ Healy, Catherine B.; Coggins, Marie A.; Van Tongeren, Martie; MacCalman, Laura; McGowan, Padraic (2014-11-01). "An Evaluation of On-Tool Shrouds for Controlling Respirable Crystalline Silica in Restoration Stone Work". The Annals of Occupational Hygiene 58 (9): 1155–1167. doi:10.1093/annhyg/meu069. ISSN 0003-4878. https://academic.oup.com/annweh/article-abstract/58/9/1155/244914.
14. ↑ Weller, Michael; Clemence, Dennis; Lau, Abe; Rawlings, Mark; Robertson, Amy; Sankaran, Bhoopathy (2024-03-01). "An assessment of worker exposure to respirable dust and crystalline silica in workshops fabricating engineered stone". Annals of Work Exposures and Health 68 (2): 170–179. doi:10.1093/annweh/wxad072. ISSN 2398-7308. https://academic.oup.com/annweh/article/68/2/170/7473352.
15. ↑ "Comparison of dust emissions when using various 3M fibre discs and grinding wheels". https://multimedia.3m.com/mws/media/1379719O/vito-report-dust-emissions-cubitron-ii-fibre-dcgw-en-version.pdf.
16. ↑ "What's the Best Way to Cut Thick Steel?". 7 August 2021. https://www.youtube.com/watch?v=XMXa1QImM54.
17. ↑ Senthilkumaran, S.; Balamurgan, N.; Arthanari, K.; Thirumalaikolundusubramanian, P. (Jan 2010). "Penetrating head injury from angle grinder: A cautionary tale". Journal of Neurosciences in Rural Practice 1 (1): 26–29. doi:10.4103/0976-3147.63098. ISSN 0976-3155. PMID 21799615. PMC 3137829. https://pmc.ncbi.nlm.nih.gov/articles/PMC3137829/.
18. ↑ Risk Control
19. ↑ 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

## External links

* Angle grinders Safework SA

* v
* t
* e

Metalworking

* v
* t
* e

Machining and computing

Computer-aided
engineering|

* 2.5D
* CAD
* CAM
* G-code
* Numerical control (NC and CNC)
* Stewart platform

Drilling and
threading|

* Die head
* Drill
* Drill bit
* Drill bit shank
* Drill bit sizes
* Drilling
* List of drill and tap sizes
* Tap and die
* Tap wrench
* Threading

Grinding and
lapping|

* Abrasive
* Abrasive machining
* Angle grinder
* Bench grinder
* Coated abrasive
* Cylindrical grinder
* Diamond plate
* Flick grinder
* Grinding
* Grinding dresser
* Grinding machine
* Grinding wheel
* Jig grinder
* Lapping
* Sanding
* Sharpening stone
* Spark testing
* Surface grinder
* Tool and cutter grinder

Machining|

* Boring
* Broaching
* Electrical discharge machining
* Electrochemical machining
* Electron-beam machining
* End mill
* Engraving
* Facing
* Hobbing
* Jig borer
* Machine tool
* Machining
* Metal lathe
* Milling cutter
* Milling machine
* Pantograph
* Photochemical machining
* Planer
* Reamer
* Rotary transfer machine
* Shaper
* Skiving machine
* Turning
* Ultrasonic machining

Machine tools|

* Angle plate
* Chuck
* Collet
* Fixture
* Indexing head
* Jig
* Lathe center
* Machine taper
* Magnetic base
* Mandrel
* Rotary table
* Wiggler

Terminology|

* Cutting fluid
* Machining vibrations
* Speeds and feeds
* Swarf
* Tolerance
* Tool and die making
* Tramp oil

* Casting
* Fabrication
* Forming
* Jewellery
* Machining
* Metallurgy
* Smithing
* Tools and terminology
* Welding

* v
* t
* e

Stonemasonry

Types|

* Ashlar
* Rustication
* Carving
* Dry stone
* Letter cutting
* Masonry
* Monumental
* Rubble
* Sculpture
* Slipform
* Snecked

Materials|

* List of stone
* Artificial stone
* Brick
* Cast stone
* Decorative stones
* Dimension stone
* Fieldstone
* Flagstone
* Gabion
* Granite
* Grout
* Marble
* Mortar
* Sandstone
* Slate

Tools|

* Angle grinder
* Bush hammer
* Ceramic tile cutter
* Chisel
* Diamond blade
* Lewis (lifting appliance)
* Non-explosive demolition agents
* Plug and feather
* Stonemason's hammer
* Straightedge

Techniques|

* Brickwork
* Flaming
* Flushwork
* Knapping
* Polygonal masonry
* Repointing
* Scabbling
* Tuckpointing

Products|

* Castle
* Hardstone carving
* Headstone (Footstone)
* Mosaic
* Sculpture
* Stone wall
* Machicolation

Organizations|

* International Union of Bricklayers and Allied Craftworkers
* Master of Work to the Crown of Scotland
* Mason Contractors Association of America
* Operative Plasterers' and Cement Masons' International Association
* Worshipful Company of Masons

* v
* t
* e

Power tools

* Sawhorse
* Workbench

* Air hammer
* Angle grinder
* Bandsaw
* Belt sander
* Blowtorch
* Circular saw
* Concrete saw
* Crusher
* Cutting torch
* Die grinder
* Drill
* Electric motor brake
* Glue gun
* Hammer drill
* Heat gun
* Impact driver
* Impact wrench
* Jackhammer
* Jigsaw
* Jointer
* Multi-tool
* Nail gun
* Power miter saw
* Nibbler
* Power trowel
* Radial arm saw
* Random orbital sander
* Reciprocating saw
* Rivet gun
* Rotary hammer
* Router table
* Sander
* Scroll saw
* Shear
* Soldering gun
* Soldering iron
* Steam box
* Table saw
* Thickness planer
* Wood router
* Wood shaper

Types of tools
Cleaning
Cutting and abrasive
Forestry
Garden
Hand
Kitchen
Machine and metalworking
Masonry
Measuring and alignment
Mining
Power
Textile
Woodworking

it:Smerigliatrice#Smerigliatrice angolare

0.00

(0 votes)

Original source: https://en.wikipedia.org/wiki/Angle grinder. Read more

|

Retrieved from "https://handwiki.org/wiki/index.php?title=Engineering:Angle_grinder&oldid=4557861"
*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template