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Waterjet cutting

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What is waterjet cutting?

Effective cutting process with high precision and quality

Waterjet cutting is an effective method for cutting materials of different types and thicknesses. More precisely, it is a cutting process (cold cutting process) with high precision and quality. In waterjet cutting, a basic distinction is made between pure waterjet cutting and abrasive waterjet cutting.

History

A brief excerpt from the history of waterjet cutting

Water jets were used in mining in the early 20th century to remove gravel or clay deposits. In California’s gold mines, it was used to separate gold veins from rocks and soil.

  • 1930

    From 1930, American and Russian engineers used it for fettling castings. At that time, pressures as low as 100 bar were used.

  • 60s

    In the late 1960s, it was used in the aircraft industry to separate parts that are sensitive to heat such as fiber composites, honeycomb and laminated materials.

  • 1974

    From 1974, hard particles were used as an additive in the waterjet, which significantly increased the quality of the workpieces and the cost-effectiveness of the process, leading to its breakthrough in industrial application.

  • 1975/76

    In 1975/76, building materials, plastics and corrugated board were separated using the process.

  • Current

    In the meantime, the technology has developed greatly and there are many more possibilities and fields of application.

Source: Wikipedia

How does waterjet cutting work?

In waterjet cutting, a workpiece is separated by a high-pressure water jet. Either filtered water or an abrasive (e.g. sand) is used in addition to the water. In this process, the water jet separates superficial and microscopic particles.

Cutting head of a waterjet cutting machine to illustrate the cutting process waterjet cutting
  1. Pressure generation

A high-pressure pump is used to generate a water jet with a pressure of 3500-6000 bar. (e.g.: operating pressure of a fire hose is approx. 17 bar)

  1. Beam generation

This jet of water is forced through a nozzle. This produces a thin jet with 2-3 Mach (air-sound velocity).

  1. Abrasive

In order to increase the cutting force by a factor of 1000 for harder materials, sharp-edged cutting sand (abrasive) is added.

Cold cutting is a cutting process that works without the application or generation of heat, which is why it is called “cold”.

Waterjet cutting does not lead to heating or thermal deformation of the material. The cut material usually remains in its original shape and does not change its original properties.

Water quality is important to ensure optimal performance.

It is important that the water is clean and free of impurities to ensure that the waterjet cutting system functions properly. Therefore, filtration and purification systems are usually used to treat the water in the best possible way.

The water pressure for waterjet cutting is 3500 – 6000 bar. Thanks to the high pressure, the water jet is able to penetrate the material and cut through it precisely.

The cutting speed depends on the material, thickness, desired accuracy of the cut.

As a rule, this is set so that the required cutting quality is achieved at high feed rates in order to make the cutting process as efficient as possible

The cutting speeds are mostly between 500 – 4000 mm/min. However, they can also be significantly lower (fine cuts for metals) or higher (plastics and foams).

Waterjet cutting is characterized by high cutting quality.

There is no heat influence, so there is no heat discoloration or deformation of the material. The cut edges are clean and precise, without burrs or chipping. The process enables cutting of complex shapes and tight curves with high accuracy.

Waterjet cutting explained quickly and simply

Waterjet cutting explained in 90 seconds.

You will learn in a short time how waterjet cutting works and what makes it so special.

We also explain how our machines and SmartCut cutting software make your job easier.

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Did you know?

The process of waterjet cutting with pure water is particularly environmentally friendly. The water here can be recycled and reused with relatively little effort.

Application areas

The 6 most common industries that use waterjet cutting

Waterjet technology is used in a wide range of industries. This is due to the versatility, precision and ability to cut a wide range of materials. Here are some of the major industries that use waterjet technology:

Metalworking

In the metal processing industry, waterjet technology is widely used to cut various metals such as steel, aluminum, stainless steel, copper and brass.

Automotive industry

In the automotive industry it is used to produce car parts, body components and prototypes. It allows cutting materials such as metal, carbon, fiberglass and plastics.

Plastics processing

Waterjet technology is also popular in plastics processing. With their help, cuts for high-quality and customized plastic parts, components and molds are possible.

Architecture and construction

In architecture & construction, it is used to cut materials such as natural stone, marble and ceramics to create complex shapes.

Stone working

In the stone processing industry, waterjet technology is used to cut and shape natural stones such as granite, marble and slate.

Food industry

In the food industry, waterjet technology is used as a hygienic cutting solution for foods such as meat, vegetables, cheese and bread.

Water jet techniques

With waterjet cutting, as already mentioned, many different materials can be cut. The desired results differ in form and structure. Therefore, there are different waterjet techniques to cut small and fine materials as well as complex three-dimensional shapes.

There are 3 main types of waterjet techniques: 2D, 3D and Microcutting.

2D cutting

With 2D cutting, or 2D cutting, is the cutting of two-dimensional materials.

In this specialty, the waterjet is used to make precise cuts in a plane. Complex shapes and contours are cut into flat materials.

Typical applications for 2D cutting are cutting metal sheets, plastic sheets, rubber, paper and other materials.

3D Cutting

3D cutting, or 3D cutting, refers to the cutting of complex three-dimensional, structures.

This technique uses a waterjet to make angled cuts in multiple planes or angles to produce three-dimensional shapes, such as 45° chamfers.

3D cutting is ideal for creating prototypes, artwork and sculptures from materials such as foam, composites, stone and metal.

Waterjet cutting with the MicroCut mini system from STM also called Micro cutting

Micro-Cutting

Microcutting, or microcutting, is the term used when cutting very small & fine contours.

Special nozzles and fine abrasives are used to make tiny cuts in materials such as semiconductors, microchips, implants and fine metal parts.

Microcutting is used in micromechanics, microelectronics, medical technology and other high-tech industries where high precision and accuracy are required.

Can waterjet cutting be used to separate all materials?

Waterjet cutting works with almost all materials up to 300mm material thickness.

Waterjet cutting is extremely versatile and can cut a wide range of materials including metal, plastic, stone, glass and composites. For soft material, cutting with pure water is sufficient. For harder materials, so-called abrasive sand is added.

The working areas of our waterjet cutting systems range from 1m x 1m(STM Cube) to 6m x 16m(STM PremiumCut IFC). However, the unique STM modular system for waterjet cutting systems stands for maximum flexibility and enables each customer to find a tailor-made solution in the desired machine size. Special systems, beyond these sizes listed here are possible on request!

At STM, we focus on your cutting requirements and offer you a customized solution for pure water or abrasive waterjet cutting of your material. Feel free to contact us or request a test cut with your material.

Types of waterjet cutting

Pure water cutting

A gentle separation process for soft materials

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In pure water cutting, soft materials are cut through exclusively with water, at a speed of Mach 2. This includes cutting foams, rubber, insulating materials, foils, felt, cork, gaskets, wood or and many other soft materials.

Another special feature of pure water cutting of plastics and foams is that even cutting thicknesses of over 300 mm are possible without any problems. The high cutting speed is an additional impressive advantage in this cutting process.

Abrasive waterjet cutting

Highest cutting performance for hard materials

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In order to achieve a higher cutting performance for hard materials, a sharp-edged cutting sand (garnet sand, commonly also called abrasive sand) is added to the water jet.

Abrasive waterjet cutting is used for materials such as stone, glass, carbon, copper, steel, aluminum, brass, sheet metal, ceramics, plastics, and many others.

As a rule of thumb, the abrasive waterjet can cut materials up to the hardness of the abrasive sand used (Mohs hardness of approx. 8) and up to a thickness of approx. 300 mm.

What materials can be cut with waterjet cutting?

In short, almost all materials

The list of materials that can be cut with a waterjet is very long. A brief overview of the possible materials.

For more details on the applications, features, benefits, technical details and FAQs on the most commonly used materials, please visit the detail page for each material.

Metal

  • Steel
  • Aluminum
  • Copper
  • Brass
  • Titanium
  • Stainless steel
  • Iron
  • etc.

Stone

  • Granite
  • Marble
  • Schiefer
  • Sandstone
  • Limestone
  • Quartzite
  • Travertine
  • etc.

Glass

  • Flat glass
  • Float glass
  • Stained glass
  • Glass tiles
  • etc.

Wood

  • Plywood
  • MDF (Medium Density Fiberboard)
  • Solid wood
  • Veneer
  • Chipboard
  • Fiberboard
  • etc.

Plastic

  • PVC (polyvinyl chloride)
  • PET (polyethylene terephthalate)
  • PE (polyethylene)
  • PP (Polypropylene)
  • ABS (Acrylonitrile Butadiene Styrene)
  • Polycarbonate
  • etc.

Carbon & Fiberglass

  • CFRP (carbon fiber reinforced plastic)
  • GRP (glass fiber reinforced plastic)
  • Aramid fiber composites
  • Hybrid composites
  • etc.

Composite

  • WPC (Wood-Plastic-Composite)
  • MMC (metal matrix composites)
  • AMC (ceramic matrix composites)
  • NMC (Natural Fiber Matrix Composites)
  • etc.

Foam

  • Polyurethane foam (PUR)
  • Polystyrene foam (EPS)
  • Polyethylene foam (PE)
  • EVA foam (ethylene vinyl acetate)
  • Neoprene foam
  • PVC foam
  • etc.

7 Advantages of waterjet cutting

An attractive choice for precise cutting

Waterjet cutting is a modern and extremely versatile cutting technique. It offers a number of impressive advantages that make it an attractive choice for accurate cutting of a wide variety of materials.

7 convincing properties of waterjet cutting stand out in particular.

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Material diversity

Cutting a wide range of materials.

No hardening of the microstructure

The water jet does not heat the material, therefore no change occurs.

3D cutting applications

Three-dimensional cutting is possible.

Small kerf width

The water jet (approx. 1mm width) cuts with very small kerf

High cutting quality

Waterjet cutting offers outstanding cut quality.

Efficient multi-head solutions

Several cutting operations can be performed simultaneously.

Low environmental impact

No toxic gases or waste are produced.

Waterjet cutting in comparison

The Swiss Army Knife of cutting methods

The waterjet is probably the most universal cutting tool for a wide range of materials and material thicknesses.

In direct comparison, the quality of the cutting edge and cutting surface, as well as the relatively small kerf, also stand out.

The graphic shows a comparison of the areas of application of the cutting processes using steel as an example.

Features of the cutting methods in comparison

The following table presents the differences between the individual cutting processes water, laser, plasma and flame cutting. From this, it is easy to see that cutting with water clearly offers the most advantages compared to the other 3 methods.

Wasser Laser Plasma Brennschneiden
Materialverzug nein ja ja ja
Aufhärtung nein ja ja ja
Gratbildung sehr gering gering ja ja
Nacharbeit notwendig sehr gering ja ja ja
Materialverlust sehr gering gering hoch sehr hoch
Toleranz 0,02 – 0,1 mm 0,01 – 0,1 mm 0,2 – 0,5 mm 1 – 2 mm
Materialstärken bis 300mm bis 30mm bis 150 mm bis 300 mm
Materialvielfalt sehr hoch gering gering gering
Verbundmaterialien ja nein nein nein
Mehrlagiges Schneiden ja nein nein nein
Mehrkopf-Schneiden ja nein ja ja
Bedenkliche Dämpfe, Gase nein ja ja ja
Strahldurchmesser / Schnittspalt 0,3 – 1,0 mm ca. 0,2 mm 1,2 mm HiFocus ca. 3mm Standard ca. 5 mm
Kleinster Lochdruchmesser < 1/5 der Materialstärke bis 1/2 der Materialstärke 0,8 bis 1,5 x der Materialstärke ca. 2 x der Materialstärke
Kleinste Stegbreite < 1/20 der Materialstärke bis 1/5 der Materialstärke ca. 3 mm ca. 8 mm

Cutting quality

The cutting speed has the most significant influence on quality and costs. The faster you cut with the waterjet, the rougher the cut. Likewise, the working pressure or feed rate and the material resistance or material thickness play a major role in the cutting quality

Depending on the cutting requirement, the greatest challenge is therefore to find the ideal compromise between the desired cutting quality and the fastest possible feed rate.

Feed

Cutting quality is mainly controlled directly by adjusting the feed rate. Basic parameters such as water pressure or sand quantity differ only minimally across manufacturers. However, it is important to consider the maximum cutting speed permitted by the technical design of various waterjet cutting systems.

Examples of feed rates for cut quality level Q3 – standard cut:

MaterialCutting speedMaterial thickness
(Stainless) Steel200 mm/min10 mm
Aluminum600 mm/min10 mm
Granite100 mm/min50 mm
MaterialCutting speedMaterial thickness
Glass1400 mm/min10 mm
Carbon1000 mm/min10 mm
Copper400 mm/min10 mm

Standards

In the field of thermal cutting technologies, there are many accompanying standards, but for waterjet cutting , there are few corresponding specifications.

In Switzerland, there is SN 214001: 2010“Non-contact cutting – Waterjet cutting – Geometric product specification and quality” – a standard that is also often used as a basis in Germany and Austria.

SN 214001 describes 5 different quality levels, defines cutting angle errors, form and position deviations, contour errors and roughness.

Quality levels

The quality of waterjet cuts are classified into 5 quality levels as is customary in the industry. A distinction is made between separation cut (Q1), rough cut (Q2), standard cut (Q3), quality cut (Q4) and fine cut (Q5).

Basically, the difference between, for example, quality cut (Q4) and cut-off cut (Q1) is 3 times the speed and thus also 3 times the cost.

Q1
Separating cut

Q3
Standard cut

Q5
Fine cut

How expensive is waterjet cutting?

The cost of waterjet cutting depends on several factors. The main factors are the type of material, material thickness, complexity of the design and machine settings.

There are also other individual factors, such as the location (cost of electricity & water), possible cutting speeds (depending on the material & the material thickness, pressure, etc.) and necessary preparatory work (e.g. data transfer, material preparations, etc.).

The best way is to tell us your requirements and we will offer you a customized solution. Feel free to contact us or request a test cut with your material.

Main factors

  • Material type
  • Material thickness
  • Design complexity
  • Machine configurations

Individual factors

  • Site costs
  • Cutting speeds
  • Preparatory work

Operating costs

Operational costs in waterjet cutting are largely composed of energy costs and wear part/maintenance costs. In abrasive waterjet cutting, the abrasive and its disposal is the proportionally largest cost factor.

Pure water cutting

Abrasive waterjet cutting

Sample cost breakdown

Pumpentyp Antriebsleistung (kW) Betriebsdruck (bar) Düsendurchmesser (mm) Max. Schnittleistung lfm/h Kosten pro Laufmeter €/lfm Verschleißteilkosten €/h Stromkosten €/h Gesamtkosten bei max. Schnittleistung
Konventionell 11 4000 0,2 12  € 0,97  € 2,50  € 1,60  € 15,74
Konventionell 19 4000 0,25 16,8  € 0,90  € 2,30  € 2,70  € 20,12
Konventionell 37 4000 0,35 33  € 0,63  € 2,50  € 5,30  € 28,59
Servoantrieb 37 4000 0,35 33  € 0,63  € 2,30  € 4,50  € 27,59
Servoantrieb 45 4000 0,4 42  € 0,58  € 2,30  € 5,60  € 32,26
Konventionell 75 4000 0,5 55,8  € 0,61  € 5,00  € 10,50  € 49,54
Ultrahochdruck 45 6000 0,25 47,4  € 0,60  € 8,00  € 6,60  € 43,04
Ultrahochdruck 75 6000 0,35 71,4  € 0,60  € 16,00  € 10,20  € 69,04

Example based on the material steel with a material thickness of 5mm.
All values in relation to mean cutting quality Q3. All data are approximate values without guarantee. All information is to be verified individually.

Waterjet cutting as a favorable alternative

Waterjet cutting is a favorable alternative due to its material diversity, which often eliminates the need for separate processing machines. Sensitive materials such as glass or ceramics, which could be damaged by other cutting methods, can also be cut gently.

The low heat influence, deformation or loss of hardness can be avoided. Complex shapes can be cut, precisely and quickly. Despite these many advantages, no toxic fumes or gases are produced, making waterjet cutting one of the most environmentally friendly cutting processes.

References

The best advertising is known to be satisfied customers

Among our references you will find customers & partners from various fields. Among them are companies from the following sectors:

  • Metal industry
  • Stone / Ceramics / Glass
  • Plastics / foam industry
  • Sealing industry
  • Prototype / plant engineering
  • Microwaterjet
  • Educational Institutions
  • Research
  • Special materials

FAQ – Frequently asked questions

The most frequently asked questions about waterjet cutting

We have collected and answered some of the most frequently asked questions about waterjet cutting. Get answers to general and specific questions about this versatile cutting technology. If your question is not answered, please feel free to contact us directly.

How does waterjet cutting work?

In waterjet cutting, a workpiece is separated by a high-pressure water jet . A high-pressure pump is used to generate a water jet with 3500-6000 bar. In this process, the water jet separates superficial and microscopic particles.

Either filtered water (pure water cutting) or an abrasive (e.g. sand) is used in addition to the water.

How much pressure is used in waterjet cutting?

Water pressure of 3,500 to 6,000 bar is common for waterjet cutting.

Is waterjet cutting just cutting with water or is there something else involved?

There are 2 types of waterjet cutting. The pure water cutting and the abrasive waterjet cutting. In abrasive waterjet cutting, sharp-edged cutting sand (abrasive sand) is added to achieve a higher cutting performance.

Pure water cutting is particularly suitable for soft materials such as foam, soft wood, and more. Abrasive waterjet cutting, on the other hand, is for harder materials, such as metal, stone, glass, and more.

How does CNC waterjet cutting work?

In CNC waterjet cutting, software and machine merge into one tool. In this process, the workpiece is usually manufactured without the employee’s supervision, thus creating new resources.

This manufacturing method is used, among other things, for the production of prototypes, in toolmaking, but also for the production of small and large series.

– Digitally import sample piece (alternatively photograph and digitize analog)
– Make necessary corrections
– Select material and material thickness
– Software calculates own costs and recommended selling price
– Generate work report (material & processing time are documented)

Are waterjet cutting systems easy to program?

Thanks to STM SmartCut, the flexibility of the waterjet can be fully exploited. At the same time, suggested strategies and the intuitive user interface make it very easy to use.

The software communicates directly between the waterjet cutting system and a standard office PC as the CNC control unit. StM SmartCut allows faster processing of cutting requirements and requires no special CNC or EDP knowledge.

The basic principle of water jet separation technology?

Waterjet cutting technology goes back to a German dentist who obtained a patent for drilling teeth at the beginning of the 19th century.

The technology of waterjet cutting in today’s industrial production, on the other hand, is based on the principle of the kinetic energy that a drop of water has when it emerges from the water nozzle at a certain speed. The water nozzle has the crucial task of concentrating the water under high pressure. The water nozzle is just large enough so that the pressure does not drop. Typically, the nozzle diameter for waterjet cutting is 0.1 – 0.5 mm.

The water droplets emerge at a certain speed depending on the pressure. At 4000 bar, for example, the jet velocity is 640 m/sec. At this speed, the water droplets separate a wide variety of soft materials such as plastics, foams, cork, felt and similar materials.

If the waterjet cutting process is to be used to cut metals, ceramics, glass or other hard materials, sand (abrasive) must be added to a mixing chamber with negative pressure after the waterjet nozzle.

Garnet sand with a grain size of 0.1 to 0.3 mm is used for this purpose. The garnet sand is very hard, sharp-edged and heavy enough to achieve a very good cutting result. At the same time, it is non-toxic and can be easily recycled and subsequently disposed of.

Typically, the water jet cutting process uses a 0.35 mm water nozzle at 4000 bar and 450 g sand/minute for cutting.

The cutting technology or the cutting process with waterjet is also very flexible, since any material starting with glass, stone, wood, ceramics, up to foam, felt, cork and metals can be cut in different thicknesses without heat input.

Can waterjet cutting be used to separate all materials?

Waterjet cutting is extremely versatile and can cut a wide range of materials including metal, plastic, stone, glass and composites. For soft material, cutting with pure water is sufficient. For harder materials, so-called abrasive sand is added.

What materials can be cut with a waterjet?

The list of materials that can be cut with a waterjet is very long. Metal, stone, glass, wood, plastic, composite, carbon & fiberglass, foam, food, and more.

How thick can the material be for waterjet cutting?

Waterjet cutting works with almost all materials up to 300mm material thickness. For pure water cutting of plastics and foams, material thicknesses of over 300mm are also possible.

Is cutting without distortion and burr-free possible?

The distortion of the cut material is brought about in conventional cutting processes by thermal influences (e.g. plasma cutting or laser cutting). Waterjet cutting is a cold cutting process and enables hard and soft materials to be separated without material deformation and without burrs.

What cutting accuracy can I expect from waterjet cutting?

Over 80% of waterjet users worldwide cut to ±0.1mm or higher accuracy.

How much is the taper of the kerf?

The resulting taper is a function of the cutting speed. The largest possible taper is equal to the maximum cutting width on the material surface (Ex: 0.8 mm) and 0.0 mm on the material underside.

As you reduce the cutting speed, the taper also gets smaller until you get parallel sides. The usual taper for precision cuts is between 0.05 and 0.10 mm.

How wide is the kerf in waterjet cutting?

The kerf is approximately as wide as the inside diameter of the focusing tube, in most applications between 0.8 and 1 mm.

What water quality is required for waterjet cutting?

The following minimum water quality requirements exist:
– pH value 7.0 – 8.5
– Carbonate hardness 20 – 60 ppm corresponds to 2 – 6 ° dH
– Calcium carbonate (Ca) 35 – 107 ppm
– Chloride content (Cl) 100 mg/l
– Inlet temperature for feed water 10 – 25 °C
– Electrical conductivity at +25°C 450 µS/cm
– Filtrate dry residue 350 mg/l
– Free dissolved chlorine 1 mg/l
– Feed water inlet pressure 0.2 – 2.5 MPa

Deviations from these values lead to shorter service lives of the high-pressure seals of the pump and the water nozzles. Therefore, a water analysis and, if necessary, appropriate water treatment is recommended.

How much water is used in waterjet cutting with 400MPa cutting pressure?

This depends on the performance of the HP pump or water nozzle. Usually between 2.22 – 14.42 l/min.

Water nozzle:
– 0.1: 0.32 l/min
– 0.15: 0.71 l/min
– 0.2: 1.22 l/min
– 0.25: 1.87 l/min
– 0.3: 2.66 l/min
– 0.35: 3.57 l/min
– 0.4: 4.60 l/min
– 0.5: 6.82 l/min

Should I cut under water when waterjet cutting?

The biggest advantage is the reduction of cutting noise to below 75 dBA. The disadvantage of underwater cutting is that it is difficult or impossible to see the workpiece during cutting.

Workpiece handling also takes place under water – unless you have a water level control in the water tank. Furthermore, it should be noted that the cutting process suffers a power reduction of approx. 5% at 1mm overlap with water.

What is abrasive waterjet cutting?

In abrasive waterjet cutting, a high-pressure waterjet is combined with abrasive abrasives. The abrasives, often garnet sand or aluminium oxide, increase the cutting performance and enable the cutting of hard materials such as metal, stone or glass.

Which abrasive is used for waterjet cutting?

Garnet sand is by far the most widely used abrasive. It convinces in the areas of acquisition costs, cutting speed, mixing head service life and minimal health risks. Other abrasives contain olive sand, aluminum oxide and some artificial materials.

How much abrasive do I need?

This depends on the working pressure and the water nozzle used. Usually between 150-450g/min. At 400 MPa working pressure is needed for optimum cutting performance:

– Nozzle 0.15 mm / Focus 0.6mm 150g/min
– Nozzle 0.25 mm / Focus 0.8mm 350g/min
– Nozzle 0.35 mm / Focus 1.0mm 450g/min

Which is better laser cutting or waterjet cutting?

Laser cutting is a very productive process. Nevertheless, the waterjet has some advantages over the laser:

– No problems with reflective materials such as brass and aluminum
No heat influence, therefore there is no burning and no change of material structure by heat
– The water jet can be used to cut heat-sensitive materials such as plastic, rubber, composites, glass, stone and very hard ceramics
– When changing materials, only the cutting speed needs to be adjusted
– Additional cutting heads can be easily attached for expanded production
Distance between nozzle and material less critical
– Waterjet systems are less expensive to purchase

Is waterjet cutting an alternative to laser cutting?

Waterjet cutting is a modern alternative to laser cutting.

A wide variety of materials can be cut flexibly with waterjet. These range from glass, plastics, wood, ceramics and metals to special metals such as sintered metal, bimetal, spring steel, titanium, Inconel or platinum, and many more.

The processing of the material takes place without the application of heat and thus without any structural changes. No further finishing of the workpiece is necessary. Compared to cutting with laser cutting systems, waterjet processing can also cut very different material thicknesses.

What are the advantages of waterjet cutting over plasma / oxyfuel flame cutting?

Plasma cutting is a heat process. It adds large amounts of heat to the workpiece and leaves a heat-affected zone.

The surface created by a water jet is generally better. There is no burr on the material, so finishing is not necessary.

The abrasive waterjet is less restricted in terms of cutting thickness and several working areas of one jet can be close together.

What are the advantages of waterjet cutting over electrical discharge machining (EDM)?

EDM is very accurate, but also very slow. An electrically conductive material is mandatory and causes a change in the material structure due to heat.

Waterjet cutting is fast, requires no conductive material and there is no change to the material structure.

What are the advantages of waterjet cutting over a milling cutter?

If you want to cut through the edge of the material as well as holes or create blind holes and threads, the abrasive waterjet is usually much faster, easier to program and also cheaper than a milling cutter.

This is mainly due to the fact that the material is cut through in one go and that no metal chips are produced.

Waterjet / Laser / Plasma / EDM – Comparison of material thickness and cutting accuracy

Waterjet cutting has a higher accuracy than can be achieved with a flame or plasma cutting system. In addition, waterjet cutting systems cut higher material thicknesses than laser systems.

What can not be separated waterjet cutting?

Waterjet cutting is not suitable for materials that dissolve or react chemically on contact with water, such as some types of rubber, certain plastics or materials that are softened by water.

Similarly, very hard or brittle materials are sometimes difficult to cut because the water jet may not be able to apply enough cutting power. In such cases, other cutting methods such as laser cutting or wire erosion may be more suitable.

How long does the workpiece support last during waterjet cutting?

The support grids or workpiece supports last for many cutting hours, provided you don’t always cut on the same spot. The grids can be moved, exchanged and reversed, as with laser or plasma cutting systems.

How long does a maintenance interval of the high-pressure pump last?

The high-pressure seals must be replaced if they leak! At a constant working pressure of 400 MPa, the seals should be replaced after 400 to 1,000 cutting hours.

How long does the focusing tube, also called focus, last?

Focuses made of good ceramic carbide last about 100 hours. Focuses made of the highest ceramic carbide quality last approx. 30% longer than focuses made of other materials.

Such a focusing tube can last up to 150 cutting hours if the diameter is increased by 0.5 mm. Many of our customers already use somewhat used foci for the production of parts where high accuracy is not required.

How long does the water nozzle last in waterjet cutting?

One sapphire nozzle lasts 25 cutting hours. A diamond nozzle (the highest nozzle quality) lasts much longer, but costs many times more.

How much is charged for contract cutting on waterjet equipment?

In most cases, contract cutting on abrasive waterjet cutting machines is charged between € 120.00 and € 220.00 per hour.

What are the operating costs of a waterjet cutting system?

The costs per hour start at € 15.00 for a small cutting head (nozzle: 0.15 mm / focus 0.6 mm) and go up to € 35.00 for a large cutting head (nozzle 0.35 mm / focus 1.0 mm).

The amount includes all machine-related costs. Working time, acquisition costs and depreciation must still be added.

How much does the abrasive cost?

The abrasive currently costs about 450 euros per ton, depending on the quality.

Which is cheaper laser cutting or waterjet cutting?

The cost of laser cutting and waterjet cutting can vary depending on the specific project. For thin materials or for large series production, laser cutting is often cheaper than waterjet cutting.

However, waterjet cutting offers greater material versatility and is often a better choice for certain materials, thicker workpieces or complex shapes.

However, the actual cost depends on the requirements and characteristics of each project.

Waterjet cutting: Is residual moisture in the process relevant?

Residual moisture is not a problem for materials with a smooth surface. The component is blown off with compressed air.

For materials that actively attract and bind water, such as wood, open-pored foams and textiles, the material should be dried afterwards. In practice, blower dryers are used for this purpose.

When and how do I use more than one cutting head?

Use multiple cutting heads if you want to create many identical parts.

Either a second cutting head is attached to the existing Z-axis, or a second Z-axis is installed to which additional cutting heads can then be attached.

It is important to note that each individual cutting head must be supplied with the same pressure and flow rate in order to be able to realize a uniform cut.

Do I have to drill a starting hole for waterjet cutting?

With most materials, the waterjet creates its own starting hole (launching point). For some composite materials, the pump pressure must be reduced and a special drilling spindle used.

What electrical connection do I need for waterjet cutting?

A connected load of at least 11 kW must be taken into account for each installed cutting valve .

How do I clamp the part to be machined during waterjet cutting?

Since the force applied to the workpiece is very small (less than 1 kg for precision cuts and less than 5 kg for average cuts), costly clamping devices are not required. Most users use simple light weights to keep their workpieces stable.

Perfectly tailored to your needs.

Waterjet cutting systems from STM

STM systems are divided into the EcoCut, MasterCut, PremiumCut, PremiumCut IFC, Cube and MicroCut product series and differ basically in size and equipment. Based on these equipment profiles, STM can configure a customized system for any requirement – from simple two-dimensional cuts to tube cutting to nested three-dimensional cuts.