View source for Water jet cutter

{{Short description|Industrial tool}}
{{Distinguish|pressure washer}}
[[File:Water jet cutter head.svg|thumb|upright|A diagram of a water jet cutter{{ordered list|high-pressure water inlet|jewel (ruby or diamond)|abrasive (garnet)|mixing tube|guard|cutting water jet|cut material}}]]

A '''water jet cutter''', also known as a '''water jet''' or '''waterjet''', is an industrial tool capable of cutting a wide variety of materials using an extremely high-pressure jet of [[water]], or a mixture of water and an [[abrasive]] substance.  The term '''abrasive jet''' refers specifically to the use of a mixture of water and an abrasive to cut hard materials such as metal, stone or glass, while the terms '''pure waterjet''' and '''water-only cutting''' refer to waterjet cutting without the use of added abrasives, often used for softer materials such as wood or rubber.<ref>{{Citation | title = About waterjets | url = http://waterjets.org/index.php?option=com_content&task=category&sectionid=4&id=46&Itemid=53 | access-date = 2010-02-13 | archive-url = https://web.archive.org/web/20100226103801/http://www.waterjets.org/index.php?option=com_content&task=category&sectionid=4&id=46&Itemid=53 | archive-date = 2010-02-26 | postscript = . | url-status = dead }}</ref>

Waterjet cutting is often used during the fabrication of machine parts. It is the preferred method when the materials being cut are sensitive to the high temperatures generated by other methods; examples of such materials include plastic and [[aluminium]]. Waterjet cutting is used in various industries, including [[mining]] and [[aerospace]], for cutting, shaping, and [[reamer|reaming]].<ref>{{Cite web|last=Guidorzi|first=Elia|date=2022-02-03|title=Waterjet Cutting History - Origins of the Waterjet Cutter|url=https://www.techniwaterjet.com/waterjet-cutting-history/|access-date=2022-02-17|website=TechniWaterjet|language=en-US}}</ref>

== History ==
[[File:Retro Systems Waterjet.jpg|thumb|Waterjet [[Numerical control|CNC]] cutting machine]]

=== Waterjet ===

While using high-pressure water for erosion dates back as far as the mid-1800s with [[hydraulic mining]], it was not until the 1930s that narrow jets of water started to appear as an industrial cutting device. In 1933, the Paper Patents Company in Wisconsin developed a paper metering, cutting, and reeling machine that used a diagonally moving waterjet nozzle to cut a horizontally moving sheet of continuous paper.<ref>Fourness, Charles A et al, [https://patents.google.com/patent/US2006499 Paper Metering, Cutting, and Reeling], filed May 22, 1933, and issued July 2, 1935.</ref> These early applications were at low pressure and restricted to soft materials like paper.

Waterjet technology evolved in the post-war era as researchers around the world searched for new methods of efficient cutting systems. In 1956, Carl Johnson of Durox International in Luxembourg developed a method for cutting plastic shapes using a thin stream high-pressure water jet, but those materials, like paper, were soft materials.<ref>Johnson, Carl Olof, [https://patents.google.com/patent/US2881503 Method for Cutting Up Plastic and Semi-Plastic Masses], filed March 13, 1956, and issued April 14, 1959.</ref> In 1958, Billie Schwacha of North American Aviation developed a system using ultra-high-pressure liquid to cut hard materials.<ref>Schwacha, Billie G., [https://patents.google.com/patent/US2985050 Liquid Cutting of Hard Metals], filed October 13, 1958, and issued May 23, 1961.</ref> This system used a {{convert|100000|psi|MPa|abbr=on}} pump to deliver a [[hypersonic flow|hypersonic]] liquid jet that could cut high-strength alloys such as PH15-7-MO stainless steel. Used to cut honeycomb laminate for the Mach 3 [[North American XB-70 Valkyrie]], this cutting method resulted in [[delamination|delaminating]] at high speed, requiring changes to the manufacturing process.<ref>Jenkins, Dennis R & Tony R Landis, ''Valkyrie: North American's Mach 3 Superbomber'', Specialty Press, 2004, p. 108.</ref>

While not effective for the XB-70 project, the concept was valid and further research continued to evolve waterjet cutting. In 1962, Philip Rice of [[Union Carbide]] explored using a pulsing waterjet at up to {{convert|50000|psi|MPa|abbr=on}} to cut metals, stone, and other materials.<ref>Rice, Phillip K., [https://patents.google.com/patent/US3212378 Process for Cutting and Working Solid Materials], filed October 26, 1962, and issued October 19, 1965.</ref> Research by S.J. Leach and G.L. Walker in the mid-1960s expanded on traditional coal waterjet cutting to determine the ideal nozzle shape for high-pressure waterjet cutting of stone,<ref>Leach, S.J. and G.L. Walker, The Application of High Speed Liquid Jets to Cutting, ''Philosophical Transactions of the Royal Society of London, Series A, Mathematical and Physical Sciences'', Vol 260, No 1110, July 28, 1966, pp.&nbsp;295–310.</ref> and Norman Franz in the late 1960s focused on waterjet cutting of soft materials by dissolving long-chain polymers in the water to improve the cohesiveness of the jet stream.<ref>Franz, Norman C., [https://patents.google.com/patent/US3524367 High Velocity Liquid Jet], filed May 31, 1968, and issued August 18, 1970.</ref> In the early 1970s, the desire to improve the durability of the waterjet nozzle led Ray Chadwick, Michael Kurko, and Joseph Corriveau of the Bendix Corporation to come up with the idea of using [[corundum]] crystal to form a waterjet orifice,<ref>Chadwick, Ray F Chadwick, Michael C Kurko, and Joseph A Corriveau, [https://patents.google.com/patent/US3756106 Nozzle for Producing Fluid Cutting Jet], filed March 1, 1971, and issued September 4, 1973.</ref> while Norman Franz expanded on this and created a waterjet nozzle with an orifice as small as {{convert|0.002|in|mm}} that operated at pressures up to {{convert|70000|psi|MPa|abbr=on}}.<ref>Franz, Norman C., [https://patents.google.com/patent/US3750961 Very High Velocity Fluid Jet Nozzles and Methods of Making Same], filed July 16, 1971, and issued August 7, 1973.</ref> John Olsen, along with George Hurlburt and Louis Kapcsandy at Flow Research (later Flow Industries), further improved the commercial potential of the water jet by showing that treating the water beforehand could increase the operational life of the nozzle.<ref>Olsen, John H., George H. Hurlburt, and Louis E. Kapcsandy, [https://patents.google.com/patent/US4216906 Method for Making High Velocity Liquid Jet], filed June 21, 1976, and issued August 12, 1980.</ref>
[[File:Waterjet cutting machine.jpg|thumb|A 5-axis waterjet cutting machine]]

=== High pressure ===

High-pressure vessels and pumps became affordable and reliable with the advent of steam power. By the mid-1800s, steam locomotives were common and the first efficient steam-driven fire engine was operational.<ref>{{cite web|title=John Ericsson|url=http://www.british-steam-fire-engines.org/John_Ericsson.html|work=British Made Steam Fire Engines|access-date=10 June 2012|url-status=dead|archive-url=https://web.archive.org/web/20120328131611/http://www.british-steam-fire-engines.org/John_Ericsson.html|archive-date=28 March 2012}}</ref> By the turn of the century, high-pressure reliability improved, with [[Schmidt high-pressure system#The Schmidt system|locomotive research]] leading to a sixfold increase in boiler pressure, some reaching {{convert|1600|psi|MPa|abbr=on}}. Most high-pressure pumps at this time, though, operated around {{convert|500|-|800|psi|MPa|abbr=on}}.

High-pressure systems were further shaped by the aviation, automotive, and oil industries. Aircraft manufacturers such as Boeing developed seals for hydraulically boosted control systems in the 1940s,<ref>Berry, Mitchell M., [https://patents.google.com/patent/US2314683 Piston Sealing Assembly], filed March 3, 1941, and issued March 23, 1943.</ref> while automotive designers followed similar research for hydraulic suspension systems.<ref>Templeton, Herbert W., [https://patents.google.com/patent/US2992817 Metering Valve Seal], filed July 11, 1958, and issued July 18, 1961.</ref> Higher pressures in hydraulic systems in the oil industry also led to the development of advanced seals and packing to prevent leaks.<ref>Webb, Derrel D., [https://patents.google.com/patent/US3004783 High Pressure Packing Means], filed August 12, 1957, and issued October 17, 1961.</ref>

These advances in seal technology, plus the rise of plastics in the post-war years, led to the development of the first reliable high-pressure pump. The invention of [[Marlex]] by Robert Banks and [[John Paul Hogan]] of the [[Phillips Petroleum Company]] required a catalyst to be injected into the polyethylene.<ref>Hogan, John Paul and Robert L. Banks, [https://patents.google.com/patent/US2825721 Polymers and Production Thereof], filed March 26, 1956, and issued March 4, 1958.</ref> McCartney Manufacturing Company in [[Baxter Springs, Kansas]], began manufacturing these high-pressure pumps in 1960 for the polyethylene industry.<ref>{{cite web|title=KMT McCartney Products for the LDPE Industry|url=http://www.kmtldpe.com/company-info.aspx|publisher=KMT McCartney Products|access-date=10 June 2012|url-status=live|archive-url=https://web.archive.org/web/20121224175547/http://www.kmtldpe.com/company-info.aspx|archive-date=24 December 2012}}</ref> Flow Industries in Kent, Washington set the groundwork for commercial viability of waterjets with John Olsen’s development of the high-pressure fluid intensifier in 1973,<ref>Olsen, John H., [https://patents.google.com/patent/US3811795 High Pressure Fluid Intensifier and Method], filed January 12, 1973, and issued May 21, 1974.</ref> a design that was further refined in 1976.<ref>Olsen, John H., [https://patents.google.com/patent/US4029440 High Pressure Fluid Intensifier and Method], filed March 16, 1976, and issued June 14, 1977.</ref> Flow Industries then combined the high-pressure pump research with their waterjet nozzle research and brought waterjet cutting into the manufacturing world.{{citation needed|reason=Flow was one of several companies doing this.  Sounds like a self-promoting claim.|date=December 2015}}

=== Abrasive waterjet ===

[[File:Evolution of the Abrasive Waterjet Nozzle.jpg|thumb|upright=1.35|The Evolution of the Abrasive Waterjet Nozzle]]
While cutting with water is possible for soft materials, adding an abrasive turned the water jet into a modern machining tool for all materials. This began in 1935 when the idea of adding an abrasive to the water stream was developed by Elmo Smith for liquid abrasive blasting.<ref>Smith, Elmo V., [https://patents.google.com/patent/US2040715 Liquid Blasting], filed June 10, 1935, and issued May 12, 1936.</ref> Smith’s design was further refined by Leslie Tirrell of the Hydroblast Corporation in 1937, resulting in a nozzle design that created a mix of high-pressure water and abrasive for the purpose of wet blasting.<ref>Tirrell, Leslie L., [https://patents.google.com/patent/US2176577 Sandblast Device], filed April 3, 1937, and issued October 17, 1939.</ref>

The first publications on modern abrasive waterjet (AWJ) cutting were published by [[Mohamed Hashish]] in the 1982 BHR proceedings showing, for the first time, that waterjets with relatively small amounts of abrasives are capable of cutting hard materials such as steel and concrete. The March 1984 issue of the Mechanical Engineering magazine showed more details and materials cut with AWJ such as titanium, aluminium, glass, and stone.  Mohamed Hashish was awarded a patent on forming AWJ in 1987.<ref name="Hashish1987">Hashish, Mohamed, Michael Kirby and Yih-Ho Pao, [https://patents.google.com/patent/US4648215 Method and Apparatus for Forming a High Velocity Liquid Abrasive Jet], filed October 7, 1985, and issued March 10, 1987.</ref> Hashish, who also coined the new term ''abrasive waterjet'', and his team continued to develop and improve the AWJ technology and its hardware for many applications. A critical development was creating a durable mixing tube that could withstand the power of the high-pressure AWJ, and it was Boride Products (now Kennametal) development of their ROCTEC line of ceramic [[tungsten carbide]] composite tubes that significantly increased the operational life of the AWJ nozzle.<ref>{{cite web|title=ROCTEC Composite Carbide Abrasive Waterjet Nozzles|url=http://www.kennametal.com/images/pdf/products_services/advanced_materials/roctecbrochure8-30-06.pdf|publisher=Kennametal Boride Abrasive Flow Products|access-date=1 July 2012|url-status=live|archive-url=https://web.archive.org/web/20081206083930/http://www.kennametal.com/images/pdf/products_services/advanced_materials/roctecbrochure8-30-06.pdf|archive-date=6 December 2008}}</ref> Current work on AWJ nozzles is on micro abrasive waterjets so that cutting with jets smaller than {{convert|0.015|in|mm}} in diameter can be commercialized.

Working with Ingersoll-Rand Waterjet Systems, Michael Dixon implemented the first production practical means of cutting titanium sheets—an abrasive waterjet system very similar to those in widespread use today.<ref name="Hashish1987" /> By January 1989, that system was being run 24 hours a day producing titanium parts for the B-1B largely at Rockwell's North American Aviation facility in Newark, Ohio.

Today, there are two different types of Abrasive Waterjets:

==== Abrasive water suspension jet (AWSJ) cutting ====
The abrasive water suspension jet (AWSJ) - often called “slurry jet” or “water abrasive suspension (WAS) jet” - is a specific type of abrasive water jet, which is used for waterjet cutting. In contrast to the abrasive water injector jet (AWIJ), the abrasive water suspension jet (AWSJ)<ref name="iw.uni-hannover.de">{{cite web|title=Wasser-Abrasiv-Suspensions-Strahl-schneiden (WASS) – Institut für Werkstoffkunde|periodical=|publisher=|url=https://www.iw.uni-hannover.de/de/forschung/forschungsschwerpunkte/unterwassertechnikum-hannover/wasser-abrasiv-suspensions-strahl-schneiden-wass/|format=|access-date=|last=|date=|year=|language=de|pages=|quote=}}</ref> is characterised by the fact that the mixing of abrasive and water takes place before the nozzle. This has the effect that, in contrast to AWIJ, the jet consists of only two components: the water and the abrasive.

Since there are only 2 components (water and abrasive) in the AWSJ, the acceleration of the abrasive grains by the water takes place with a significantly increased efficiency compared to the AWIJ.<ref>{{citation|periodical=Procedia Engineering|title=Measurement and Analysis of Abrasive Particles Velocities in AWSJ|volume=149|at=pp.&nbsp;77–86|issn=1877-7058|date=2016-01-01|language=de|doi=10.1016/j.proeng.2016.06.641|doi-access=free|last1=Zeleňák |first1=M. |last2=Foldyna |first2=J. |last3=Linde |first3=M. |last4=Pude |first4=F. |last5=Rentsch |first5=T. |last6=Fernolendt |first6=J. |last7=Poort |first7=H.U. |hdl=20.500.11850/119156 |hdl-access=free }}</ref> The abrasive grains become faster with the WASS than with the WAIS for the same hydraulic power of the system. Therefore, comparatively deeper or faster cuts can be made with the AWSJ.

AWSJ cutting, in contrast to the AWIJ cutting process described below, can also be used for mobile cutting applications and cutting underwater, in addition to machining demanding materials.<ref>{{cite web|title=Hochleistungsverfahren bezwingt Hochleistungswerkstoffe|periodical=|publisher=|url=https://www.tu-chemnitz.de/tu/pressestelle/aktuell/9596|format=|access-date=|last=Pressestelle|date=8 June 2023|language=de|pages=|quote=}}</ref><ref>{{cite web|title=ConSus – DAs Wasser-Abrasiv-Suspensionstrahl-System mit kontinuierlicher Abrasivmittelzufuhr|periodical=|publisher=Ingenieur-Spiegel. Band 3-2019. Public Verlagsgesellschaft und Anzeigenagentur mbH, Bingen, S. 23–25.|url=https://studium.hs-ulm.de/de/users/625229/Documents/Ingenieurspiegel%20ConSus_IS_3_2019.pdf|format=|access-date=|last=Prof. Dr.-Ing.Michael Kaufeld, Prof. Dr.-Ing. Frank Pude, Dipl.-ing. Marco Linde|date=March 2019|language=de|pages=|quote=}}</ref><ref name="iw.uni-hannover.de"/> Examples include bomb disposal,<ref>{{cite web|title=Bombenentschärfungen: Neue Wasserstrahl-Technik|periodical=|publisher=|url=https://www.ndr.de/nachrichten/schleswig-holstein/Bombenentschaerfungen-Neue-Wasserstrahl-Technik,bombe3342.html|access-date=|last=NDR|date=|year=|language=de|pages=|quote=}}</ref> as well as the dismantling of offshore installations<ref>{{cite web|title=Decommissioning Project Completed for Middle East Offshore Platform|periodical=|publisher=|url=http://www.materialsperformance.com/news/2019/01/decommissioning-project-completed-for-middle-east-offshore-platform|format=|access-date=|last=|date=|year=|language=|pages=|quote=}}</ref> or the dismantling of reactor pressure vessel installations in nuclear power plants.<ref>{{cite web|title=Spektakulärer Robotereinsatz: Stäublis Unterwasser-Roboter zerlegt radioaktive AKW-Bestandteile|periodical=|publisher=|url=https://automationspraxis.industrie.de/robotik/spektakulaerer-robotereinsatz-unterwasser-roboter-von-staeubli-zerlegt-radioaktive-akw-bestandteile/|format=|access-date=|last=|date=2021-01-07|language=de-DE|pages=|quote=}}</ref>

==== Abrasive Water Injector Jet (AWIJ) cutting ====
{{more citations needed section|date=May 2023}}
The AWIJ<ref>{{cite web|title=Wasser-Abrasiv-Injektor-Strahl-schneiden (WAIS) – Institut für Werkstoffkunde|periodical=|publisher=|url=https://www.iw.uni-hannover.de/de/forschung/forschungsschwerpunkte/unterwassertechnikum-hannover/wasser-abrasiv-injektor-strahl-schneiden-wais/|format=|access-date=|last=|date=|year=|language=de|pages=|quote=}}</ref> is generated by a water jet that passes through a mixing chamber (a cavity) after exiting the water nozzle and enters a focusing tube at the exit of the mixing chamber. The interaction of the water jet in the mixing chamber with the air inside creates negative pressure, the water jet entrains air particles. This negative pressure is used for the pneumatic transport of the abrasive into the chamber (the abrasive is led to a lateral opening (bore) of the mixing chamber by means of a hose).

After contact with the abrasive material in the mixing chamber with the water jet, the individual abrasive grains are accelerated and entrained in the direction of the focusing tube. The air used as a carrier medium for transporting the abrasive into the mixing chamber also becomes part of the AWIJ, which now consists of three components (water - abrasive - air). In the focusing tube, which is (should be) optimised in its length for this purpose, the abrasive is further accelerated (energy transfer from the water to the abrasive grain) and the AWIJ ideally leaves the focusing tube at the maximum possible abrasive grain speed.

=== Waterjet control ===

As waterjet cutting moved into traditional manufacturing shops, controlling the cutter reliably and accurately was essential. Early waterjet cutting systems adapted traditional systems such as {{Citation needed span|date=December 2024|[[Pantograph#Milling machines|mechanical pantographs]]}} and [[CNC]] systems<ref name="Ye, 2024">{{cite web |last1=Ye |first1=Ronan |title=What is Waterjet Cutting: Process, Advantages, Applications & Costs |url=https://www.3erp.com/blog/waterjet-cutting/ |website=3ERP |access-date=7 December 2024 |archive-url=https://web.archive.org/web/20241207132859if_/https://www.3erp.com/blog/waterjet-cutting/ |archive-date=December 7, 2024 |location=Independence, MO, USA <!-- from "About Us" page --> |language=en |date=16 July 2024 |url-status=live |at=sec. 4}}</ref> based on John Parsons' 1952 NC milling machine and running [[G-code]].<ref>{{cite web|title=Machining & CNC Manufacturing: A brief history|url=http://www.me.wpi.edu/MFE/HCCM/cnc.html|publisher=Worcester Polytechnic Institute|access-date=25 June 2012|archive-url=https://web.archive.org/web/20040820154254if_/http://www.me.wpi.edu/MFE/HCCM/cnc.html|archive-date=2004-08-20|url-status=dead}}</ref> Challenges inherent to waterjet technology revealed the inadequacies of traditional G-Code.{{Citation needed|date=December 2024|reason=Next source does not discuss G-Code}} The accuracy depends on varying the speed of the nozzle as it approaches corners and details.<ref>{{cite web|last=Olsen|first=John H.|title=What Really Determines the Time to Make a Part?|url=http://www.drolsenslab.com/abrasive-waterjet-technology/what-really-determines-the-time-to-make-a-part/|work=Dr Olsen's Lab|access-date=28 June 2012|url-status=dead|archive-url=https://web.archive.org/web/20120506172842/http://www.drolsenslab.com/abrasive-waterjet-technology/what-really-determines-the-time-to-make-a-part/|archive-date=6 May 2012}}</ref> A major breakthrough came in the early [['90s]], when John Olsen developed systems to precisely position the waterjet nozzle while accurately specifying the speed at every point along the path and utilizing common PCs as a controller.<ref name="Olsen, 1999">{{cite web |last1=Olsen |first1=John H. |title=Motion Control for Quality in Jet Cutting |url=https://patents.google.com/patent/US5892345 |website=Google Patents |access-date=6 December 2024 |archive-url=https://web.archive.org/web/20241206232532if_/https://patents.google.com/patent/US5892345 |archive-date=December 6, 2024 |language=en |date=2019-05-30 |url-status=live |orig-date=Filed 14 May 1997}}</ref>
[[File:Largest Waterjet New England Seacoast Great Bay Northeast USA America Speed Fast Quick Material Cutting Tolerance Control Omax Westinghouse Newington NH WEC Specialty.jpg|alt= Large Water Jet Abrasive Cutting Machine|thumb|upright=1.35|Large water jet abrasive cutting machine]]

== Operation ==
All waterjets follow the same principle of using high-pressure water focused into a beam by a nozzle. Most machines accomplish this by first running the water through a high-pressure [[pump]]. There are two types of pumps used to create this high pressure; an intensifier pump and a direct drive or crankshaft pump. A direct drive pump works much like a car engine, forcing water through high-pressure tubing using plungers attached to a [[crankshaft]]. An intensifier pump creates pressure by using hydraulic oil to move a piston forcing the water through a tiny hole.<ref name="Waterjet pumps">{{cite web|title=Crankshaft vs. Intensifier pump|url=http://waterjets.org/index.php?option=com_content&task=view&id=183&Itemid=51|website=WaterJets.org|publisher=Olsen Software LLC|access-date=14 June 2016|url-status=live|archive-url=https://web.archive.org/web/20160806170136/http://waterjets.org/index.php?option=com_content&task=view&id=183&Itemid=51|archive-date=6 August 2016}}</ref><ref name="types of pumps">{{cite web|title=Types of Pumps|url=http://www.wardjet.com/03-how-it-works#PumpTypes|website=www.wardjet.com|access-date=14 June 2016|url-status=live|archive-url=https://web.archive.org/web/20160617014342/http://www.wardjet.com/03-how-it-works#PumpTypes|archive-date=17 June 2016}}</ref> The water then travels along the high-pressure tubing to the nozzle of the waterjet. In the nozzle, the water is focused into a thin beam by a jewel orifice. This beam of water is ejected from the nozzle, cutting through the material by spraying it with the jet of speed on the order of [[Mach number|Mach]] 3, around {{convert|2500|ft/s|abbr=on}}.<ref>{{Cite web|url=http://web.mit.edu/2.972/www/reports/abrasive_water_jet/abrasive_waterjet.html|title=2.972 How an Abrasive Waterjet Cutter Works|website=web.mit.edu}}</ref> The process is the same for abrasive waterjets until the water reaches the nozzle. Here abrasives such as [[garnet]] and [[aluminium oxide]], are fed into the nozzle via an abrasive inlet. The abrasive then mixes with the water in a mixing tube and is forced out the end at high pressure.<ref name="Waterjet Nozzles">{{cite web|title=Basic Waterjet Principles|url=http://waterjets.org/index.php?option=com_content&task=category&sectionid=4&id=46&Itemid=53|website=WaterJets.org|publisher=Olsen Software LLC|access-date=14 June 2016|url-status=live|archive-url=https://web.archive.org/web/20100226103801/http://www.waterjets.org/index.php?option=com_content&task=category&sectionid=4&id=46&Itemid=53|archive-date=26 February 2010}}</ref><ref name="How it works">{{cite web|title=How Does a Waterjet Work?|url=https://www.omax.com/learn/how-does-waterjet-work|website=OMAX Abrasive Waterjets|access-date=14 June 2016|url-status=live|archive-url=https://web.archive.org/web/20160602024437/https://www.omax.com/learn/how-does-waterjet-work|archive-date=2 June 2016}}</ref>

== Benefits ==
An important benefit of the water jet is the ability to cut material without interfering with its inherent structure, as there is no ''heat-affected zone'' (HAZ). Minimizing the effects of heat allows metals to be cut without warping, affecting [[Tempering (metallurgy)|temper]]s, or changing intrinsic properties.<ref>Lorincz, Jim. Waterjets: Evolving from Macro to Micro, ''Manufacturing Engineering'', Society of Manufacturing Engineers, November 2009</ref> Sharp corners, bevels, pierce holes, and shapes with minimal inner radii are all possible.<ref>{{cite web |url=http://www.techniwaterjet.com/waterjet-advantages/ |title=Waterjet Cutting Advantages |url-status=live |archive-url=https://web.archive.org/web/20170921193116/http://www.techniwaterjet.com/waterjet-advantages/ |archive-date=2017-09-21 }}</ref>

Water jet cutters are also capable of producing intricate cuts in material. With specialized software and 3-D machining heads, complex shapes can be produced.<ref name="ReferenceA">Lorincz, Waterjets: Evolving from Macro to Micro.</ref>

The [[wikt:kerf|kerf]], or width, of the cut can be adjusted by swapping parts in the nozzle, as well as changing the type and size of the abrasive. Typical abrasive cuts have a kerf in the range of {{convert|0.04|to(-)|0.05|in|mm|abbr=on}}, but can be as narrow as {{convert|0.02|in|mm}}. Non-abrasive cuts are normally {{convert|0.007|to(-)|0.013|in|mm|abbr=on}}, but can be as small as {{convert|0.003|in|mm}}, which is approximately that of a human hair. These small jets can permit small details in a wide range of applications.

Water jets are capable of attaining accuracy down to {{convert|0.005|in|mm}} and repeatability down to {{convert|0.001|in|mm}}.<ref name="ReferenceA"/>

Due to its relatively narrow kerf, water jet cutting can reduce the amount of scrap material produced, by allowing uncut parts to be nested more closely together than traditional cutting methods. Water jets use approximately {{convert|0.5|to(-)|1|gal|L|abbr=on}} per minute (depending on the cutting head's orifice size), and the water can be recycled using a closed-loop system. Waste water usually is clean enough to filter and dispose of down a drain. The garnet abrasive is a non-toxic material that can be mostly recycled for repeated use; otherwise, it can usually be disposed of in a landfill. Water jets also produce fewer airborne dust particles, smoke, fumes, and contaminants,<ref name="ReferenceA"/> reducing operator exposure to hazardous materials.<ref name="applications1">{{cite web |url=http://www.jetedge.com/content.cfm?fuseaction=dsp_applications_101 |title=Company |publisher=Jet Edge |access-date=2009-06-11 |url-status=live |archive-url=https://web.archive.org/web/20090223061453/http://jetedge.com/content.cfm?fuseaction=dsp_applications_101 |archive-date=2009-02-23 }}</ref>

[[Meatcutting]] using waterjet technology eliminates the risk of [[cross contamination]] since the contact medium is discarded.{{Citation needed|date=May 2023}}

== Versatility ==
[[File:Water jet cutter tool.jpg|thumb|A water jet cutting a metal tool]]

Because the nature of the cutting stream can be easily modified the water jet can be used in nearly every industry; there are many different materials that the water jet can cut. Some of them have unique characteristics that require special attention when cutting.

Materials commonly cut with a water jet include textiles, rubber, foam, plastics, leather, composites, stone, tile, glass, metals, food, paper and much more.<ref>{{Cite web|title=What is a Waterjet cutting machine ?|url=https://www.thibaut.fr/en/waterjet/|access-date=2020-11-10|website=Thibaut|date=30 November 2017 |language=en}}</ref> "Most ceramics can also be cut on an abrasive water jet as long as the material is softer than the abrasive being used (between 7.5 and 8.5 on the Mohs scale)".<ref name="materials waterjet can cut">{{cite web|title=What Materials Can a Waterjet Cut?|url=https://www.omax.com/learn/what-materials-can-waterjet-cut|website=OMAX Abrasive Waterjets|access-date=14 June 2016|url-status=live|archive-url=https://web.archive.org/web/20160602005605/https://www.omax.com/learn/what-materials-can-waterjet-cut|archive-date=2 June 2016}}</ref> Examples of materials that cannot be cut with a water jet are tempered glass and diamonds.<ref name="applications1" />  Water jets are capable of cutting up to {{convert|6|inch|mm|abbr=on}} of metals and {{convert|18|inch|mm|abbr=on}} of most materials,<ref>{{cite web|url=https://www.kmt-waterjet.com/waterjet-cutting-faqs_01.aspx|title=Waterjet Cutting - Cut Metal, Stone, Paper, Composites|website=www.kmt-waterjet.com|url-status=live|archive-url=https://web.archive.org/web/20170405073816/https://www.kmt-waterjet.com/waterjet-cutting-faqs_01.aspx|archive-date=2017-04-05}}</ref> though in specialized coal mining applications,<ref>{{Cite web|url=https://www.thibaut.fr/en/waterjet/|title=What is a Waterjet cutting machine ?|website=Thibaut|date=30 November 2017 |language=en|access-date=2019-10-14}}</ref> water jets are capable of cutting up to {{convert|100|feet|m|abbr=on}} using a {{convert|1|inch|mm|abbr=on}} nozzle.<ref>{{cite web |url=http://blog.kmt-waterjet.com/waterjetting-technology-pipe-straighteners/ |title=Waterjetting Technology – Pipe Straighteners &#124; KMT Waterjet &#124; KMT Waterjet |access-date=2017-09-18 |url-status=live |archive-url=https://web.archive.org/web/20170505223520/http://blog.kmt-waterjet.com/waterjetting-technology-pipe-straighteners/ |archive-date=2017-05-05 }}</ref>

Specially designed water jet cutters are commonly used to remove excess bitumen from road surfaces that have become the subject of binder flushing. Flushing is a natural occurrence caused during hot weather where the aggregate becomes level with the bituminous binder layer creating a hazardously smooth road surface during wet weather.{{Citation needed|date=May 2023}}

== Availability ==
Commercial water jet cutting systems are available from manufacturers all over the world, in a range of sizes, and with water pumps capable of a range of pressures. Typical water jet cutting machines have a working envelope as small as a few square feet, or up to hundreds of square feet. Ultra-high-pressure water pumps are available from as low as {{convert|40000|psi|MPa|abbr=on}} up to {{convert|100000|psi|MPa|abbr=on}}.<ref name="ReferenceA"/>  There has also been a growth in small, desktop-sized machines that operate at pressures under 10kpsi.

== Process ==
There are six main process characteristics of water jet cutting:
# Uses a high-velocity stream of ultra high-pressure water {{convert|30000|-|90000|psi|MPa|abbr=on}} which is produced by a high-pressure pump with possible abrasive particles suspended in the stream.
# Is used for machining a large array of materials, including heat-sensitive, delicate, or very hard materials.
# Produces no heat damage to the workpiece surface or edges.
# Nozzles are typically made of [[tungsten carbide]].<ref>{{cite web |url=https://www.techniwaterjet.com/waterjet-cutting-history/ |title=Waterjet Cutting History: Origins and Timeline |last=Schlick |first=Jonathan |date=11 March 2023 |website=Techni Waterjet |publisher=Techni |access-date=15 April 2024 |quote=Boride Corp develops abrasive waterjet cutting nozzles of ceramic tungsten carbide material.}}</ref>
# Produces a taper of less than 1° on most cuts, which can be reduced or eliminated entirely by slowing down the cut process or tilting the jet.<ref name="Taper elimination">{{cite web|last1=Olsen|first1=John|title=Improving waterjet cutting precision by eliminating taper|url=http://www.thefabricator.com/article/waterjetcutting/improving-waterjet-cutting-precision-by-eliminating-taper|website=TheFabricator.com|publisher=FMA Communications|access-date=18 July 2015|url-status=live|archive-url=https://web.archive.org/web/20150722114701/http://www.thefabricator.com/article/waterjetcutting/improving-waterjet-cutting-precision-by-eliminating-taper|archive-date=22 July 2015}}</ref>
# Distance of the nozzle from the workpiece affects the size of the kerf and the removal rate of material. Typical distance is {{convert|.125|in|mm|abbr=on}}.

Temperature is not much of a factor because the water used also acts as a [[coolant]].

== Edge quality ==
Edge quality for water jet cut parts is defined with the quality numbers Q1 through Q5. Lower numbers indicate rougher edge finish; higher numbers are smoother. For thin materials, the difference in cutting speed for Q1 could be as much as 3 times faster than the speed for Q5. For thicker materials, Q1 could be 6 times faster than Q5. For example, {{convert|4|in|mm}} thick aluminium Q5 would be {{convert|0.72|in/min|mm/min|abbr=on}} and Q1 would be {{convert|4.2|in/min|mm/min|abbr=on}}, 5.8&nbsp;times faster.<ref>{{cite web |url=http://www.wardjet.com/02-waterjet-relationship-parameters.html |title=Waterjet Relationship Parameters |url-status=live |archive-url=https://web.archive.org/web/20100909174125/http://www.wardjet.com/02-waterjet-relationship-parameters.html |archive-date=2010-09-09 }}<!-- This is not a copyright violation; see http://www.wardjet.com/copyright.asp--></ref>

== Multi-axis cutting ==
{{Main article|Multiaxis machining}}
{{more citations needed section|date=May 2023}}

In 1987, Ingersoll-Rand Waterjet Systems offered a 5-axis pure-water waterjet cutting system called the Robotic Waterjet System.  The system was an overhead gantry design, similar in overall size to the HS-1000.

With recent advances{{When|date=May 2023}} in control and motion technology, 5-axis water jet cutting (abrasive and pure) has become a reality. Where the normal axes on a water jet are named Y (back/forth), X (left/right) and Z (up/down), a 5-axis system will typically add an A axis (angle from perpendicular) and C axis (rotation around the Z-axis). Depending on the cutting head, the maximum cutting angle for the A axis can be anywhere from 55, 60, or in some cases even 90&nbsp;degrees from vertical. As such, 5-axis cutting opens up a wide range of applications that can be machined on a water jet cutting machine.

A 5-axis cutting head can be used to cut 4-axis parts, where the bottom surface geometries are shifted a certain amount to produce the appropriate angle and the Z-axis remains at one height. This can be useful for applications like weld preparation where a bevel angle needs to be cut on all sides of a part that will later be welded, or for taper compensation purposes where the kerf angle is transferred to the waste material&nbsp;– thus eliminating the taper commonly found on water jet-cut parts. A 5-axis head can cut parts where the Z-axis is also moving along with all the other axes. This full 5-axis cutting could be used for cutting contours on various surfaces of formed parts.

Because of the angles that can be cut, part programs may need to have additional cuts to free the part from the sheet. Attempting to slide a complex part at a severe angle from a plate can be difficult without appropriate relief cuts.

== See also ==
* [[CryoJet]]
* [[Laser cutting]]
* [[Plasma cutting]]
* [[Electrical discharge machining]]
* [[Digital modeling and fabrication]]

== References ==
{{Reflist|colwidth=35em}}

== External links ==
* [https://science.howstuffworks.com/environmental/energy/question553.htm?srch_tag=bpxjdx6ovrkxduau3tyysmkxyci2oypt How Can Water Cut Through Steel?], HowStuffWorks.com video
* [https://wazer.com/why-waterjet/ Why Waterjet?] Here’s an in-depth educational piece detailing how a waterjet works, what it can cut, and how waterjets compare to other CNC cutting technologies.
* [http://www.techniwaterjet.com/how-it-works/ Waterjet Cutting – How it Works], A look inside the physics of achieving high pressure water for waterjet cutting.
*[https://www.thibaut.fr/en/waterjet/ What is a Waterjet cutting machine?], A definition of the process
*[https://www.metalworkingsuppliers.com/mw/water-jet-cutting-machine-history/ Milestones in the History of Water Jet Cutting]
* [https://textilelearner.net/water-jet-fabric-cutting-machine/ Fabric Cutting by Water Jet Cutting Machine]

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