Waterjet Cutting Explained: How High‑Pressure Water Shapes Materials

Waterjet cutting is a CNC cutting process in which a waterjet at very high pressure is used to cut material.

In this process, a high-pressure pump forces water through specialized tubing, and out through a nozzle at very high speeds (up to 900 m/sec). The nozzle focuses the waterjet onto the workpiece and is controlled by CNC.

Types of Waterjet Cutters

There are two major types of waterjet; pure waterjet and abrasive waterjet.

• Abrasive waterjets comprise a mixture of water and an abrasive substance such as garnet and aluminium oxide.
• Pure waterjets, on the other hand, contain only pure water.

Materials

Waterjet cutting can cut various materials including hard material like aluminum, steel, copper, other metals and stone. It can also cut relatively soft material such as wood, rubber, plastic, and paper. For cutting hard material, abrasive waterjets are used. Pure water is used for cutting soft material. The maximum thickness that this process can cut depends on the material.

Benefits and Limitations

Waterjet cutting has some advantages over plasma and laser cutting. To begin with, it is the most precise of the three, with tolerances between 0.05 and 0.1 mm. Also, waterjet cutting does not involve any heat and so no heat-affected zone is created in the workpiece. Thanks to this and the precision of waterjet cutting, parts created by the process hardly require any post-processing or finishing.

Other benefits of waterjet cutting are its ability to cut intricate and complex shapes, minimal material wastage, and the recyclability of the water used.