How Material Thickness Affects Cutting Speed and Quality!

When it comes to cutting thick materials with laser and waterjet, thickness isn’t just a number—it’s the single most important factor that can make or break your project. Whether you're prototyping precision components or executing large-scale fabrication, the thickness of the material directly affects cutting speed, edge quality, and cost-efficiency.

Thicker materials take longer to cut, require more energy, and demand different settings or equipment configurations. That means more time on the machine and more money out of your budget. Understanding how thickness interacts with laser and waterjet cutting technologies helps you avoid delays, reduce waste, and choose the most cost-effective process from the start.

Cutting Thick Materials with Waterjet

When it comes to cutting thick materials with laser and waterjet, waterjet stands out as the go-to solution for flexibility. Waterjet cutting uses a high-pressure stream of water—often mixed with abrasive particles—to erode material with extreme precision. This makes it especially well-suited for cutting thick metals, composites, ceramics, stone, and even laminated materials.

One of the key advantages of waterjet is its ability to cut thicker materials without compromising edge quality. While laser cutters struggle with heat-affected zones (HAZ) in dense materials, waterjets operate with a cold-cutting process. That means no thermal distortion, no warping, and a clean, smooth edge—even on materials up to 6 inches thick or more.

The trade-off? Speed. Waterjet cutting is significantly slower than laser, especially as thickness increases. A thicker workpiece requires a slower traverse rate to maintain accuracy and prevent tapering. That affects cycle times and, ultimately, project turnaround. However, this slower speed is often worth it for projects that require versatility, precision, and high-quality finishes.

For engineers and fabricators working with a wide variety of materials and dimensions, waterjet is the preferred method for cutting thick materials, especially when edge integrity and material compatibility are top priorities.

Cutting Thick Materials with Laser

In the world of cutting thick materials with laser and waterjet, lasers are prized for their speed and precision—but they come with limitations when thickness increases. Unlike waterjet, laser cutting relies on a concentrated beam of light to melt, burn, or vaporize material. While this method is fast and accurate for thin to moderately thick materials, cutting thicker sections demands significantly higher power output and more careful control.

For instance, cutting mild steel up to 1 inch thick requires a high-powered fiber or CO₂ laser—often in the 6kW to 12kW range. As the thickness increases, so does the need for auxiliary gases like oxygen or nitrogen to assist the cut and maintain edge quality. However, even at high power levels, laser cutting thick materials introduces challenges like taper, reduced edge smoothness, and slower cutting speeds compared to thinner sheets.

Another major consideration is the heat-affected zone (HAZ). Thicker materials absorb more heat, leading to wider HAZs that can affect material properties, increase warping, and reduce dimensional tolerance. This is especially critical in applications where metallurgical integrity or tight fitment is essential.

Despite these limitations, laser cutting is still a viable choice for thick materials—especially metals—if you have the right equipment and understand its constraints. The key is balancing power, speed, and thermal impact for your specific material and thickness.

Accuracy and Taper at Different Thicknesses

When cutting thick materials with laser and waterjet, maintaining dimensional accuracy becomes increasingly complex. One of the most common challenges is taper—where the cut is narrower at the bottom than at the top—especially prominent in waterjet cutting. In laser cutting, this can also occur due to beam divergence or excessive heat input, particularly at high thicknesses.

For both technologies, kerf width—the width of the cut path—can vary depending on thickness, material type, and cutting parameters. On thicker plates, a wider kerf may reduce part-to-part precision if not properly accounted for in the design or toolpath programming.

To manage this, professionals apply techniques like pierce dwell control, multi-pass cutting, or bevel compensation. Using high-quality abrasive in waterjet or optimizing focal length and gas assist in laser systems also helps improve edge definition.

Ultimately, the best results come from fine-tuning your process: running test cuts, adjusting speeds and pressures, and calibrating nozzle or beam alignment based on material thickness. These precision practices help ensure that even thick materials are cut with tight tolerances and minimal secondary processing—making them ready for fitment, welding, or finishing right off the machine.

Choosing the Right Method for Your Thickness

Selecting between laser and waterjet cutting isn’t just about availability—it’s about matching your material thickness with the right tool for speed, precision, and cost-efficiency. When cutting thick materials with laser and waterjet, the right decision can reduce machining time, minimize rework, and improve part quality.

Use laser cutting when you're working with thin to moderately thick metals, need faster turnaround, and require tight tolerances with minimal cleanup. On the other hand, waterjet is ideal for ultra-thick materials, heat-sensitive components, and non-metallic or layered materials that would degrade under laser heat.

Here’s a practical comparison:

Example: A client fabricating 3" thick stone panels for architectural cladding chose waterjet to preserve edge finish and avoid cracks. Meanwhile, a manufacturer of 0.5" stainless brackets used laser to reduce cycle time by 40% without compromising fit.

Your material, design, and performance requirements should guide the decision—not just the machine on hand.

Conclusion

When it comes to cutting thick materials with laser and waterjet, success lies in understanding how material thickness impacts every part of the process—from speed and precision to cost and edge quality. No single cutting method is universally better; the “best” choice always depends on the job’s specific requirements.

Laser cutting delivers fast, high-precision results on thin to moderately thick metals, making it ideal for projects that demand speed and tight tolerances. Waterjet cutting, on the other hand, excels in handling very thick, layered, or heat-sensitive materials—offering versatility and a superior finish without thermal distortion.

The key takeaway? Let the part’s use case determine the cutting method. Consider the material, its thickness, required tolerances, and the importance of edge quality. Matching the right technology to the right thickness ensures fewer errors, smoother production, and more cost-effective outcomes.

By planning ahead and aligning your process with your material, you maximize both quality and efficiency—turning thick, tough materials into precision-cut components every time.