When you're cutting steel or aluminum plate over one inch thick, you need a method that delivers precision, power, and consistency without compromising material integrity. That’s where water jet cutting shines.
Industries such as shipbuilding, energy, construction, industrial food processing, and heavy equipment manufacturing depend on thick metal plate stock to create durable, long-lasting products. However, cutting these materials cleanly and efficiently is a challenging task. Water jet cutting provides unique advantages that make it the ideal solution for this task. Let’s explore.
Plasma cutting is a fast and cost-effective process for cutting thin to medium materials. But when it comes to thick plate, plasma systems can struggle producing quality edges with precision. Plasma cutting also typically produces rough edges and burrs that need removal. Given the extremely high temperature of this process, these defects are quite hard, adding time and cost.
There are also practical limitations with plasma cutting when it comes to material thickness. 4 inches of thickness is generally considered the limit of plasma cutting systems making them less than ideal for heavy duty thick plate applications.
Oxyfuel cutting is effective for thick steel but is limited to ferrous metals, leaving a large heat-affected zone (HAZ). That can mean reduced structural integrity at worst and increased post-processing at best, both of which add to your production costs.
Laser cutting excels at thin materials but significantly loses speed and effectiveness as material thickness increases. Depending on laser power, thicknesses above 1 to 2 inches may be totally impractical.
In general, lasers often use oxygen gas as an assist to help cut speeds, but this leaves oxidized edges that must be chemically or mechanically cleaned before painting or welding. This oxidation from laser cutting is a double whammy in the sense that it not only creates additional damage that requires machining and finishing. It also hardens the metals resulting in more difficult machining resulting in additional labor and costs from cut to finish.
Compared to all the thermal processes mentioned above, water jet systems produce clean, accurate cuts in nearly any material. They leave no HAZ, no oxidation, and can deliver a much higher quality cut edge, resulting in significantly reduced machining and finishing time - in many applications water jets can produce parts with no secondary finishing required.
When comparing feed rates and cycle times for various processes in thick plate cutting applications, there are several things to take into consideration. While it is true water jet cutting feed rates are slower during the actual cut – when considering the impact of manual finishing and secondary operations, the total time from raw material to a finished product can often be faster using water.
But how does that make sense? It all comes down cut quality and finishing.
The HAZ produced by heat-based cutting systems leave parts with a cut edge that requires machining and finishing – often involving manual labor. This is compounded in thick plate cutting by the surface area of the cut edge. Combined with the hardening of the material, heat-based systems like plasma and lasers can significantly extend machining and finishing times. The cool-cutting process of water-based systems allows for either completely finished or near-finished parts coming off the machine negating the longer cut times.
Another advantage of water jet cutting systems is their ability to easily integrate 5-axis technology into the cutting head. This is not a given with competing technologies and can often add prohibitive costs to laser-based systems and are mostly not available with plasma-based systems. This capability also enables water jets to control and adjust for the taper produced during cuts – allowing for much more complex and precise geometries and finishes. This capability is either not possible, or incredibly expensive with heat-based cutting systems.
Cutting thick metal isn’t just a scaled-up version of working with sheet stock. It causes other cutting methods to struggle and produce undesirable results, including:
Because of the nature of the cool cutting process, water jet systems eliminate these outcomes and delivers consistent, high-quality results.
Now, let’s take a close look at how water jet cutting systems overcome the challenges of cutting thick plate stock material, starting with the avoidance of a HAZ.
Water jet is a cold-cutting process. That means no thermal distortion, no hardened or brittle edges, and no loss of tempering. For applications where material properties are critical to performance (such as structural beams or aerospace parts), this is a significant advantage because it eliminates secondary steps to address HAZ-caused problems and minimizes waste when material properties cannot be recovered.
These issues are compounded when cutting thick plate materials with heat-based systems. The thicker the material, the larger the surface area on the cut edge. This results in a significantly larger HAZ that needs careful and expensive machining post-cutting adding significant finishing time and potentially costs to any process.
Water jet cutting systems deliver smooth, accurate cuts with minimal taper, even on materials several inches thick. In many cases, edges come off the table ready to use, without the need for secondary grinding, sanding, or cleanup. First-cut finishes that meet specifications are another specialty of water jet cutting.
Unlike thermal cutting methods, water jets don’t care if a metal is reflective, heat-sensitive, or even non-metallic. From hardened tool steel to thick aluminum to stone composites, a water jet handles it all with ease. It’s not a stretch to say a water jet can cut nearly any material you throw at it.
With the right system and setup, a water jet can easily slice through plate 6 inches thick. In fact, the limitation on materials thickness generally comes down to the practical question of how tall of a workpiece can fit below the cutting head (Jet Edge has specialized machines to handle extended z-axis travel using high-rail gantries, click here to learn more). Few other processes can maintain that level of precision across such a wide range of materials and thicknesses.
Water jet is a non-contact process, which means no blades to dull, no overheating, and no tool degradation over time. The only cutting head components subject to wear are the orifice and nozzle, which last longer when made from high-quality materials. The result is consistent performance across long production runs with minimal maintenance.
Water jet systems may have a slightly higher upfront purchase cost compared to plasma or oxyfuel cutting, but that difference is paid back quickly in increased capability and labor cost savings.
Compared to laser systems, water jets require a significantly lower expenditure. Be cautious if someone tells you a laser system has a similar price to a water jet machine – that will commonly only be possible with a totally unequal comparison. Laser systems configured to process thick plate and with 5-axis capability can easily cost in excess of $1 million – significantly more than even the most robust and customized water jet systems.
Considering the incredible flexibility, extreme capability and opportunity for labor cost savings mean the water jet will continue to return incredible dividends year after year. The total value proposition becomes very clear:
Over time, those savings add up, especially when you’re working with expensive or high-volume materials. The bottom line is this: any additional upfront investment delivers substantial savings for years to come, generating an ROI that your financial team will appreciate.
When it comes to cutting thick plate metal, these systems stand in a class of their own. They cut cleanly without heat, maintain edge integrity across a wide range of materials, and reduce the need for time-consuming (and costly) secondary processes.
If you’re working with thick, high-value metal plate and need results you can rely on, a Jet Edge water jet system is a wise investment in quality, productivity, and long-term performance. Let’s talk about how Jet Edge can tame your toughest thick plate cutting challenges with industry leading precision and reliability.
Need help cutting thick metals? Talk to Jet Edge today and discover how we harness its full power across our water jet cutting systems, including advanced 5-axis applications that push the limits of what’s possible and expand your opportunities.
Contact us today to learn how to increase the services you offer your customers and reduce costs through enhanced productivity. You can also call us toll-free at 1-800-JET-EDGE (538-3343), internationally at +1-763-497-8700 or visit our website jetedgewaterjets.com to learn more.
Since 1984, Jet Edge has been designing and manufacturing Ultra-High-Pressure Water jet technology that doesn't back down. Our systems are used around the world in a broad range of industries from the world's leading airlines, to automotive, aerospace and industrial manufacturers, and machine job shops.
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