Waterjet Cutting Processes

It might surprise some people that waterjets can cut through a range of hard materials, including metals, wood, and concrete. With high enough velocity and pressure, a waterjet can cut the same intricate curves as laser or plasma cutting tools.

Waterjet cutting dates back to the middle of the 19th century when miners used low-pressure jets to mine for Gold. Industrial waterjet cutting services began in the 1930s. The pressures generated were low compared to those of today, and the technology only handled softer materials, like paper.

Laser Cutting

More Information about Waterjet Cutting Technology

These days, softer materials are still cut by waterjet, but the bulk of industrial waterjet technology involves extremely tough materials of up to 10″ thick. As well as waterjet cutting steel, many waterjet cutting services specialize in cutting Aluminum, Copper, and Brass. Even Titanium can be cut this way. Waterjets can be used on composite materials of up to 4″ thick. Only very brittle materials, such as Tempered (or safety) glass, are unsuitable for waterjet cutting, as they will shatter.

Waterjet cutting uses pure water or water that contains an abrasive solution. The former is applied to softer materials, such as rubber, plastic and foams. For harder materials, such as steel or granite, powdered jewel abrasives (ruby or diamond), are always added. The mixture circulates at high velocity, adding a powerful grit action to the waterjet.

How Waterjet Cutting Machines Work

Drivers often use jet washers to ‘cut’ off clumps of dirt from their cars. A waterjet cutter works on a similar principle. The main differences are the diameter of the nozzle, which is much smaller, and the pressure of the water. Waterjet technology uses between 20,000 and 55,000 PSIU, though some waterjet cutting machines can operate at 100,000 PSI. Water velocities can reach over 900 mph with precision waterjet cutting tolerances within 0.002”.

Forcing water through a tiny nozzle at high velocity and pressure creates a lot of energy. This energy goes into the cutting of the material. To achieve such enormous forces, the waterjet cutting machine is connected to a high-pressure water pump, turning the waterjet into a powerful and precise cutting tool. By modifying the stream, it can be used to cut a wide selection of materials, creating a variety of finishes. Depending on the cutting speed, finishes achieved can be rough or fine.

Advantages of a Waterjet Metal Cutting Machine

A significant advantage of a waterjet cutter is that it does not generate any heat. Other types of cutting tool use heat or friction, and these will affect the material being cut, creating a ‘heat-affected zone’ (HAZ). Waterjet cutting creates no HAZ, so there is less wasted material, but, more importantly, no molecular or structural changes around the edge of the cut.

With a laser or plasma cutter, the heat generated in the localized zone can also change the molecular properties of the material, causing ‘edge hardening’, distortion or micro-cracks. These changes will add stress to the material as it cools, further compromising its integrity.

The waterjet cutting process is odorless and produces virtually no dust or hazardous vapors. This keeps the operator safe and means that waterjet cutting tools are easily safety compliant.

As well as cutting, waterjets can also shape and carve materials, leaving edges burr-free. Waterjet cutting has many industry-specific applications. These include waterjet cutting body and engine parts, flanges, interior trim and circuit boards.

Waterjet cutting is a versatile and highly productive cold-cutting technology. It has become increasingly popular among the aerospace, automotive, medical and electronics industries. In time, waterjet cutting services may surpass those that offer only laser cutting. Learn more about Metals 28’s waterjet cutting by speaking with one of our team members.