Waterjet cutting and CNC machining (milling, turning) are both high-precision manufacturing processes, but waterjet cutting offers distinct advantages in several key areas:

1. No heat-affected zone

CNC machining generates frictional heat, which can cause material hardening, warping, or microcracks. Waterjet cutting is a cold-cutting process that generates absolutely no heat, so it does not alter the material’s original properties. This makes it an ideal choice for processing heat-sensitive alloys, composite materials, and hardened steel.

2. Wider Range of Applicable Materials

CNC machining struggles with soft, elastic, or layered materials such as rubber, foam, gaskets, and carbon fiber—tool pressure can cause these materials to deform or delaminate. Waterjet cutting can cut virtually any material, from titanium alloys and granite to glass, plastics, and even food, without the need to change tools or make special adjustments.

3. No Tool Wear, Low Changeover Costs

CNC machining requires expensive carbide or diamond tools, which wear out, break, and need frequent replacement. Waterjet cutting uses only water and garnet—these consumables are inexpensive and require no sharpening. For small-batch or prototype production, waterjet cutting completely eliminates tooling costs.

4. Greater single-pass cutting thickness

CNC machining of thick plates or deep cavities requires multiple passes and tool changes, resulting in longer cycle times. Waterjet cutting can cut steel over 6 inches (150 mm) or foam over 12 inches (300 mm) in a single pass; thickness is limited primarily by the machine’s Z-axis travel.

5. No complex clamping required for thin sheets

CNC machining of thin sheets typically requires vacuum chucks or double-sided tape to prevent vibration. Waterjet cutting is a non-contact process that exerts virtually no lateral force on the workpiece; thin sheets require only simple support and do not need heavy-duty fixtures.

Conclusion: CNC offers greater advantages when machining internal threads, blind holes, or high-precision, high-volume metal parts. However, if material integrity, absence of heat damage, and process versatility are priorities, waterjet cutting is the superior choice.

To sum up, waterjet cutting machines can cut nearly all types of metals, including steel, stainless steel, aluminum, copper, brass, titanium, bronze, and high-performance alloys. It is a safe, efficient, and cost-effective choice for modern metal fabrication.