Waterjet cutting of natural stone: why pierce all start holes first?

Waterjet cutting is well suited to natural stone, from simple components to intricate shapes, internal cutouts and complex geometries. With materials that are hard yet brittle, however, accuracy along the cutting path is only part of the picture. How the cut begins is just as important.

One of the most demanding stages is piercing through the full thickness of the slab. This creates the start hole from which the cutting head will subsequently follow the programmed contour. With a suitable cutting strategy, all start holes can be pierced first, using parameters selected specifically for this stage.

Why does this matter? How can it help reduce cracking and chipping? And what makes CNC waterjet cutting such a versatile technology for stone fabrication? Let’s look at the complete process.

Natural stone: hard, but brittle

Granite, marble, quartzite and limestone are valued for their durability, appearance and resistance to everyday wear. From a cutting perspective, their properties are more complex.

Natural stone can be very hard while remaining brittle. Its structure is not always uniform: natural veins, different minerals and local variations can affect how the slab responds to machining.

This makes it particularly important to control the stage at which the jet first enters solid material. Chipping or cracking can compromise the finished part and, with high-value stone components, may mean starting again with a new piece of material.

Which CNC technologies are used for stone cutting?

Modern stone fabrication shops use several CNC technologies. Their capabilities overlap, but each has applications where it performs particularly well. The differences involve more than the shapes they can produce: the number of operations, level of automation and total time needed to complete a part also matter.

Diamond saws and CNC bridge saws

Diamond saw blades are highly productive for sizing stone slabs and making long, straight cuts. Modern CNC bridge saws can also make angled cuts and bevels, and carry out programmed sequences without manually repositioning each part.

For more complex geometries, however, the shape and diameter of the blade remain limiting factors, particularly for tight radii, enclosed cutouts and intricate internal contours.

CNC stone machining centers

CNC stone machining centers are particularly useful when a part requires additional tooling operations. They can perform milling, drilling, edge profiling, grooving and more complex three-dimensional machining.

Their main advantage is the ability to perform multiple operations at one workstation, often with automatic tool changes. They are especially useful when a cut component needs further shaping or finishing.

CNC waterjet cutting

Abrasive waterjet cutting uses a narrow stream of water and abrasive, guided by CNC motion control. It can produce external and internal contours, holes, curves, tight radii and irregular shapes without the geometric restrictions imposed by a circular saw blade.

Another key advantage is automation of the complete cutting sequence. Once the CNC program is prepared, the machine can carry out successive piercing operations and cut multiple holes and contours without changing tools or transferring the slab between operations.

For intricate parts, this can shorten the overall production cycle, even when the linear cutting speed is lower than that of a saw.

The technology is not limited to flat profiles. Waterjet machines with multi-axis cutting heads can also perform angled cuts, bevel cutting and more complex 3D geometries.

No single technology replaces all the others. A bridge saw may be the most productive choice for straightforward slab sizing, while a machining center is better suited to milling operations. For complex cutting, waterjet combines geometric flexibility with a high level of automation.

ECKERT Pro-X 3D five-axis waterjet cutting head.

How does abrasive waterjet cutting work on stone?

Hard mineral materials are cut using an abrasive waterjet. An abrasive, typically garnet, is added to a stream of water at very high pressure.

The high-velocity mixture leaving the nozzle removes material through controlled erosion. The cutting head follows the CNC program, so the finished shape is defined by the programmed toolpath.

This makes it possible to cut simple components as well as holes, irregular edges, curves, lettering, decorative patterns and parts that require the jet to cut at an angle.

A five-axis waterjet head extends these capabilities to angled cuts, bevels and more complex three-dimensional geometries.

You can find more information in our guide to stone cutting.

What is piercing in waterjet cutting?

When a cut starts within the slab rather than at an existing edge, the jet must first pass through the full material thickness. This stage is called piercing.

The jet initially acts on the stone surface and progressively creates a channel through the material. Once it breaks through the underside, there is a complete start hole. The cutting head can then follow the lead-in and begin cutting the programmed contour.

This is the key difference between piercing and established cutting. During cutting, the jet already has an open path through the material. During piercing, that path is still being formed.

For natural stone, this initial stage requires carefully selected piercing parameters.

Piercing a stone slab to prepare start holes before waterjet contour cutting.

Why pierce all start holes before cutting the contours?

A part with several separate contours may require multiple start points. Instead of switching directly from piercing to cutting at each contour, the program can separate the work into two stages: first pierce all the start holes, then return to them to cut the shapes.

This pre-piercing strategy offers several practical benefits when it suits the material, geometry and machine configuration.

1. Low-pressure piercing helps reduce cracking and chipping

Because stone is brittle, the jet’s initial entry needs to be controlled. Piercing can be carried out at a lower pressure than contour cutting, reducing the intensity of the initial impact on the material.

Appropriate low-pressure piercing parameters help reduce the risk of chipping or cracking while the jet is opening a passage through the slab. The benefit comes from controlling the piercing conditions, rather than simply performing the holes earlier in the sequence.

2. Each contour has a prepared start hole

Once the jet has passed through the full thickness, the start hole is ready. When the head returns during the cutting stage, it can begin the lead-in from that prepared opening.

This is particularly useful for parts with multiple enclosed cutouts, each of which needs its own entry point.

3. Separate piercing and cutting stages reduce parameter changes

Piercing may require different settings from those used for subsequent cutting. Completing the start holes first allows the machine to perform this part of the program as one piercing sequence.

The machine can then switch to the cutting parameters and return to the prepared start holes. This reduces repeated changes between piercing and cutting settings for each individual contour. The effect on total cycle time depends on the toolpath layout, travel distances and machine configuration.

A typical sequence is:

Define the start points → pierce all start holes → switch to cutting parameters → cut the contours from the prepared holes.

4. Pierce points can be placed away from the finished edge

Where the geometry and CNC program allow, the pierce point can be positioned in material that will later become scrap.

A short lead-in then takes the cutting head from the start hole to the required contour. This keeps the initial piercing location separate from the edge that remains on the finished part.

This is especially useful when the appearance and integrity of visible edges are important.

Watch stone piercing and waterjet cutting in practice

The video shows a practical example of the sequence: the machine first pierces a series of start holes using settings selected for that stage, then returns to those points to begin cutting the programmed contours.

The stone waterjet cutting process, step by step

CNC control and a suitable piercing strategy organize the process into a sequence of defined stages:

1. Prepare the part geometry and CNC cutting program.
2. Define the start point for each toolpath.
3. Pierce the start holes through the full thickness of the stone.
4. Switch to the parameters required for contour cutting.
5. Return the cutting head to the prepared holes and cut the programmed shapes.

The video demonstrates the process using a decorative pattern with multiple separate cutouts. This geometry clearly illustrates the role of the start holes, but the same approach can be used for other parts that require several independent cutting paths.

What can you make with waterjet stone cutting?

The freedom to follow complex toolpaths makes waterjet suitable for both repeat production and custom stone fabrication.

Typical applications include:

• stone countertops and worktops, including sink cutouts and faucet holes,
• architectural stonework and facade panels,
• stair components and flooring,
• holes and internal cutouts,
• irregular profiles,
• stone mosaics and inlays,
• decorative medallions and patterns,
• logos and lettering,
• components with angled cuts,
• bevels and angled edges,
• more complex geometries using a multi-axis cutting head.

The available operations depend on the machine configuration, cutting head, process parameters, material type and thickness.

Tight radii, curves and narrow features illustrate the intricate geometry possible with waterjet stone cutting.

Which stone and related materials can a waterjet cut?

Abrasive waterjet cutting is used for a wide range of materials processed by stone fabricators and manufacturers of interior fittings.

Granite

For hard materials such as granite, waterjet is particularly useful for holes, unusual contours and parts with frequent changes in cutting direction.

Marble

Waterjet cutting of marble requires appropriate process parameters and adequate slab support. Natural variations within the stone can make some areas more susceptible to damage than others.

Quartzite, limestone and sandstone

Waterjet can also cut other types of natural stone. The parameters should be adapted to the properties, structure and thickness of each material.

Sintered stone, engineered stone and ceramics

Although these are not natural stone in the strict sense, they are widely processed in stone fabrication shops. Waterjet can produce both standard profiles and demanding internal cutouts and detailed shapes in these materials.

Waterjet vs. bridge saw vs. CNC machining center: compare the complete process

When comparing stone cutting technologies, linear cutting speed is only one factor. In production, the number of operations needed to turn a raw slab into a completed component is equally important.

A CNC bridge saw can be highly productive for long, straight cuts. If the part needs milling, drilling, edge profiling or additional surface shaping, a CNC stone machining center may be the more suitable choice.

Waterjet offers particular advantages when a single part contains multiple contours, internal cutouts, tight radii and changes in direction. The machine can cut these features automatically within one CNC program, without changing tools or transferring the slab between cutting operations.

A multi-axis head adds angled cutting, bevel cutting and 3D capabilities.

A waterjet does not always need a higher linear cutting speed to complete the cutting work sooner. The advantage may come from fewer operations, fewer setups and greater automation between the raw slab and the cut component. Any required edge finishing still needs to be included in the overall production plan.

The best choice therefore depends on the parts being produced. A bridge saw, machining center and waterjet can complement one another within the same facility.

How to choose a CNC waterjet cutting machine for stone

When selecting a stone waterjet cutting machine, look beyond the pump’s maximum pressure. For a stone fabrication shop, the complete system matters, from programming and toolpath preparation to cutting head control.

Key factors to consider include:

• working area and slab capacity,
• supported material thickness range,
• high-pressure pump type,
• control over piercing parameters,
• abrasive metering and delivery,
• positioning accuracy,
• 2D or multi-axis cutting head capabilities,
• cut taper compensation,
• CNC software and toolpath preparation,
• availability of service support and consumable parts.

The right configuration depends on the production mix. A shop producing mainly countertops will have different requirements from a business making architectural stonework, decorative pieces or three-dimensional components.

Opal Waterjet: 2D, bevel and 3D stone cutting

Opal Waterjet is an ECKERT CNC waterjet cutting machine for a broad range of materials, including natural stone, ceramics, sintered stone and engineered stone.

Depending on the configuration, the machine can perform conventional 2D cutting or be equipped with the Pro-X 3D five-axis cutting head.

The head allows the jet to tilt by up to ±60°. In addition to taper compensation, this enables bevel cutting, angled cuts and more advanced three-dimensional shapes.

These capabilities extend waterjet beyond flat profile cutting, allowing one technology to handle a wider range of components.

Opal Waterjet CNC machine for abrasive waterjet cutting.

Want to explore how waterjet stone cutting could fit your production? Contact us to discuss a machine configuration suited to your materials and the parts you produce.

Explore the machine: Opal Waterjet CNC cutting system.