What is Waterjet?

The abrasive waterjet process works by cutting metal or other materials using a focused stream of highly pressurized water mixed with abrasive aggregate. The cutting head is Computer Numerically Controlled (CNC), achieving a precision of ±0.003″ per side.

High-pressure water hits the material at three times the speed of sound, carrying fine garnet abrasive in the stream with it. This combination of water and garnet cleanly erodes the material without transferring any heat into the process. Below is an example comparing a plasma-cut part to the same part cut on one of our waterjet machines:

Plasma-cut part (left) vs. Waterjet-cut part (right)

Cold-cutting and a total lack of a Heat-Affected-Zone (HAZ) on the finished parts are just a few of the advantages to waterjet cutting. Below is a chart to help compare some of the other differences between waterjet and other similar CNC cutting processes:

Waterjet Plasma Laser Wire EDM
Process Precise erosion process using ultra high pressure water and abrasive garnet Burning/melting process using high temperature ionized gas arc Melting process using concentrated laser light beam Micro thermal erosion process using electrical discharge
Materials Any material from foam up to hardened steels and high density ceramics Conductive metals only; primarily steel, stainless steel and aluminum. Primarily steel, stainless and aluminum; can also cut other materials with special setup or handling Electrically conductive metals only; no composites or plastics
Thickness 12" Z constraint is only limit to thickness on most material Up to 2-3", depending on material Generally 1" or less, depending on materials Generally 24" or less
Part Accuracy Up to 0.003" Up to 0.010" Up to 0.001" Up to 0.0001"
Edge Quality No Heat-Affected-Zone, sandblasted edge, small kerf Large Heat-Affected-Zone, burned or melted edge, slag, and large kerf Moderate Heat-Affected-Zone, darkened edge, fine kerf Minimal Heat-Affected-Zone, smooth edge quality, very fine kerf

Waterjet Cutting Will Save You Money

Milling parts out of thick blanks or plate? Waterjet cutting the rough profile of the part can save substantial amounts of valuable machining time and reduce costly wear on the cutting bits as well. With our experience in material utilization and close part nesting, additional savings can be realized in reduced material costs as well. Blanks are not work hardened or heated by the waterjet process, so there is no change in their machining properties.

Waterjet cut blank (top) and the final machined part (bottom)
Waterjet cut blank (top) and the final machined part (bottom)

Piece costs may also be drastically reduced by cutting through multiple layers at one time. Large production runs and blanket purchase orders may also qualify for substantial cutting discounts. Contact us for information on quantity discounts.

Waterjet can cut at a range of speeds, regardless of material type. We will tailor the cutting speed to meet your part tolerance and edge quality requirements. For example, hog outs will be run at a faster speed, while parts to print will be run at a slower speed.

Advanced Capabilities for Special Projects

Traditional waterjet, laser, and plasma machines do not cut parts with a perfectly perpendicular edge. All of the above processes introduce taper on the parts as the cutting medium removes more material from the top of the plate than the bottom.

Colorado WaterJet offers dynamic cutting for situations where edge perpendicularity is critical. By adjusting the cutting angle, our machines can put all of the taper onto the scrap sections of the material, leaving the parts with straight edges and clean corners.

Dynamic cutting is also desirable for architectural projects and artwork that can be viewed from both sides as the cut profile will look the same regardless of whether the front or the back of the piece is viewed.

For more information about cut speeds and dynamic cutting, please read our Edge Quality and Tolerance Guide.


Colorado WaterJet also has extensive experience with part fixturing and secondary operation cutting. With special jobs ranging from cutting bolt holes into cast pump housings to re-profiling race car brake pads, we can help you overcome the challenges of a fast paced and demanding business world.

Colorado WaterJet also has 5-axis cutting capabilities, which can be utilized for three dimensional (3D) shapes, such as weld joints and bevels up to 45 degrees. Material flatness is critical to tight tolerance 5-Axis cutting. Please contact us to discuss if 5-axis cutting is applicable to your project.

Our cutting envelope can handle material as large as 78”x157” and we have experience cutting metals and composites up to 12” thick. If you have something larger or thicker, give us a call.