When it comes to machining extruded aluminium products with intricate internal shapes that standard tools can’t reach, thick profiles that would take endless milling passes, or precision parts where even minimal heat distortion would ruin dimensional accuracy, waterjet cutting is often the obvious solution.
We saw this firsthand with a client who brought us a profile combining complex geometry, varying thicknesses, and extremely dense sections. Milling it conventionally would have required multiple passes, adding up to hours of machining for a single piece and driving up costs. With waterjet cutting, the job was completely redefined and became a lot more efficient.
So what exactly is waterjet cutting? How does it compare to lasers, CNC, or saws? When is it the best choice and when can other methods outperform it, even for precise or complex parts?
What is waterjet cutting?
Waterjet cutting aluminium uses a high-pressure jet of water mixed with abrasive particles to erode material with extreme precision. It’s a cold cutting process. No heat, no burning, no distortion. This makes it ideal for aluminium, a metal known for warping or hardening under high temperatures.
Unlike saws or lasers, waterjet cutting works by erosion, gradually removing material in a controlled way. The result is clean edges, no burrs, and virtually zero thermal stress.
Waterjet cutting vs other methods
• Waterjet vs laser cutting aluminium: Laser cutting is fast and excellent for thin sheets of steel or stainless steel. But with aluminium, the reflective surface and low melting point can cause problems, like heat distortion, microcracks, and hardening around the cut. Waterjet avoids all that.
• Waterjet vs CNC machining aluminium: CNC machining is perfect for certain operations like milling, drilling, tapping. But when you need intricate shapes, sharp internal corners, or material removed without tool access, CNC hits its limits. Waterjet doesn’t rely on tool geometry, so it can create complex cuts in one go.
• Waterjet vs saw cutting aluminium: Saws are cost-effective for straight cuts on standard extrusions. But when thickness increases or designs become decorative or complex, waterjet delivers more precision and versatility.
When should you use waterjet cutting?
• Thick material: Cutting through solid aluminium blocks or thick profiles without warping or melting the edges.
• Complex or curved cuts: Creating intricate internal shapes, rounded corners, or custom openings that standard machines can’t handle.
• No thermal impact: Essential for parts where heat can alter material properties or dimensional accuracy.
• Unreachable sections: Machining areas that saw blades or end mills physically can’t access.
• Aesthetic features: Designing architectural or decorative elements where edge quality and detail matter.
When is waterjet cutting not the right process for aluminium machining?
Of course, waterjet cutting isn’t always the most efficient solution. It comes with its own challenges, such as the setup and preparation required before running the machine. If your batch of aluminium pieces isn’t large enough, the prep and post-machining work may outweigh the benefits.
In some cases, a press with a custom tool can outperform a waterjet. For example, we had a client who needed a complex extruded aluminium product that initially looked like a job for a waterjet. Instead, our engineers developed a dedicated press tool that delivered the exact geometry in half the time.
The challenge is that obtaining custom tools is normally expensive and time-consuming so it cancels out the efficiency gains. At ALUCAD, we solve this by designing and manufacturing our own tooling in-house. Using a dedicated CNC machine with electro-erosion technology (EDM), we can produce custom tools quickly and cost-effectively. This opens the door to methods that can surpass even waterjet cutting in efficiency and precision for highly complex aluminium shapes.
ALUCAD’s approach to smart cutting
We will always evaluate your extruded aluminium product design to determine the most cost-effective and technically appropriate machining process.
And if that turns out to be waterjet cutting, we’ve got the equipment and expertise to do it right.
Contact us today and find out how we can bring your vision to life in bespoke extruded aluminium products.