Advantages of Waterjet

Advantages of Waterjet Cutting

Waterjet cutting is simply one of the most advantageous and fastest growing machining processes around.

Some listed advantages to using Waterjet Cutting
Amazing Quality Finish
No Heat Affected Zone
No mechanical stresses

Amazing Quality Finish using Waterjet Machinery

Compared to saw cutting, routing, plasma cut, and laser cutting; Waterjet cut finish stands alone. With a smoother, more sandblasted look, free of burnt edges, chips, burrs, and slag: it can save you in unnecessary finishing costs. Waterjet cutting is in fact considered a “finish cut” and is typically used for signs and displays, most popular for its esthetics. This transposes over for many different industries because the finish is typically the smoothest and cleanest

.MILCO Waterjet - Cut Quality Guage

No Heat Affected Zone with Waterjet

Unlike laser or plasma cutting that could cause burning or melting, where the cut areas material can become chemically altered due to heat, Waterjet cut parts remain unaffected, due to the fact that water is the medium being used. Water is well known for its insulation and absorption of heat. This can be very critical on applications where the material cannot show any signs of burning or discoloration, or on materials that cannot be cut with laser due to burning; with toxins released into the atmosphere. With waterjet, very little heat is created, generated or even transferred to the part. This is extremely handy for working on tool steels, stainless steels, exotic alloys and other metals where heat could actually change the properties of the metal.  Also true for plastics, acrylics,composites, laminates and phenolics.


The final result is that no heat affected zone (HAZ) on the material is created. With the absence of a HAZ, you can secondary machine without hardening the material, generating poisonous fumes, recasting, or warping. You can also machine parts that have already been heat treated.

No Mechanical Stresses

The very nature of Waterjet cutting places no mechanical stresses into the work-piece. No side pressures are created because waterjet pressure is forced downward, forcing the material onto the table, therefore clamping and fixturing is very minimal and could practically be non-existent. Because there is no metal on metal contact not heat created, waterjet machining does not introduce any stresses into the material as well.

Waterjets vs. Lasers

Laser cutting uses a laser focused onto the material intended to melt, burn and vaporize the material. The laser can be comprised of gas (such as CO2) or solid-state. The beam can be static, where the material progresses in front of the laser, or the laser can move across the material.

Advantages of waterjets

Cut more materials!

  • Waterjets can cut reflective materials like copper and aluminum that lasers cannot.

  • Waterjets can cut a wide range of material with no change in setup.

  • Waterjets can cut heat sensitive materials that lasers will ruin.

No heat-affected zone! (HAZ)

  • Waterjet cutting does not heat your part. There is no thermal distortion, which can occur with lasers. Waterjets do not change the properties of the material.

Environmentally friendly

  • Abrasivejets typically use garnet as the abrasive material. Garnet is non-reactive that is biologically inert. No noxious fumes, (vaporized metal) and no risk of fires.

Material Uniformity not important!

  • Lasers need the material to be relatively flat (uniform).

  • When cutting over uneven surfaces, focus can be lost thus losing cutting power.

  • Modern Pressures of waterjet exceed 60,000 psi which posses a more consistent cutting power over uneven material.

Better tolerances on thicker parts

  • Waterjetting offers better tolerances on parts thicker than 0.5″ (12 mm).

Thicker materials

  • Waterjets easily handle from 1/2″ through 10″.

  • Lasers lose practicality at cutting thicknesses of 0.5″

Better edge finish

  • Due to the nature of Waterjetting, cuts have a fine sand-blasted surface finish.

  • Laser cuts tend to have a rougher edge, which may need additional machining operations to clean up.

Waterjets vs. Lasers

Waterjets vs. Electrical Discharge Machining (EDM)

EDM is when an electrical arc rapidly discharges between an electrode and the work-piece material. The series of arcs removes metal by melting it and vaporizing it, essentially eroding the metal using electricity. Particles are flushed away by circulating non-conducting fluid (de-ionized water). EDM is more capable of intricate shapes in hardened metals that are extremely difficult to machine using traditional methods.

Advantages of waterjets

Many parts that an EDM would do can be done faster and cheaper on an abrasivejet, if the tolerances are not extreme.

  • New Waterjet technology allows for tolerances of up to +/-.003″!

  • Abrasive jets are much faster than EDM, which slowly removes the metal.

  • Non-conductive materials that EDM cannot touch, such as glass, wood, plastic, and ceramic are a breeze for waterjet.

  • There is almost no limit to the type of materials that can be machined with waterjets.

  • Uniformity of material not important

  • A waterjet will retain much of its cutting power over uneven material. Such material changes would cause wire EDM to lose consistency.

  • Waterjets make their own pierce holes

  • For Wire EDM, a hole needs to be in the material, which has to be done by separate process.

  • Waterjets can pierce their own material which requires no additional fixturing.

  • Make bigger parts

  • The waterjet table / tank capacity is much larger and can handle a much larger sheet than the typical EDM work table.

Waterjets vs. Plasma & Flame Cutting

Plasma cutting involves a pressurized stream of gas which is blown at high speed while an electrical arc is introduced. This causes some of the gas to become hot plasma. The gas is 27,000° F (15,000° C) which melts the metal it comes into contact with.

Advantages of waterjets

  • Waterjet can cut materials that do not easily melt (Granite, Cement, Ceramic) or that are destroyed by melting (many laminates, aluminums, exotics).

  • Precision is enhanced by no slag or left over melted metal along the cutting edge as left by Plasma.

Waterjets vs. CNC Milling

CNC Milling can perform a variety of operations on material such as cutting, drilling, lathing, and planing.
Modern mills are six-axis machines that can perform complex sequences rapidly and precisely.

Advantages of waterjets

Waterjets can machine brittle materials, pre-hardened materials, and difficult materials such as Titanium, Hastalloy, Inconel, Stainless and Hardened Tool Steels that CNC Milling does not exceed in cutting.

  • Waterjets are frequently used for complimenting or replacing milling operations.

  • Used for roughing out parts prior to milling, or for providing secondary machining on parts that just came off the mill.


Waterjets vs. Stamping / Punch Presses

A punch press uses a set of punches and dies to form parts out of metal. The metal is formed and cut by the punch press into a part, which may have secondary machining done to it or not. Coins are a common part that are formed using punch presses. The typical commercial punch press exerts about 20 tons of pressure.


Advantages of waterjets

    • Waterjets have a lower cost-per-piece for short runs than a die press, because of the expense (and time) involved in creating the dies and punches. Creating the drawing for a part on a waterjet machine is all that’s needed to begin machining the part, where with a punch press, the drawing is usually only the first step to creating the die.

    • Lateral forces with a waterjet are negligible, which means that holes can be placed very close to the material edge, which is not the case with a punch press. Waterjets can also work with very thick materials, while punch presses are limited in thickness to the amount of pressure they can apply. And, of course, waterjets can work with many different types of materials, including brittle materials and laminates .

    • Some stamping houses are using waterjets for fast turn-around and rapid prototyping work. Waterjets make a complimentary tool for punch presses because they offer a wider range of capability for similar parts. For high production of thin sheet-metal, the stamp will be more profitable in many cases, but for short runs, difficult material, and thick material, waterjets have their place.

  • Waterjets also play a big part as just one part in a larger manufacturing process. For example, waterjets are often used to machine features into an existing part, or to do pre-machining to remove material before precision finishing on other machinery.