{"id":4683,"date":"2026-03-12T23:45:45","date_gmt":"2026-03-12T15:45:45","guid":{"rendered":"https:\/\/www.intouchray.com\/?p=4683"},"modified":"2026-05-06T12:52:09","modified_gmt":"2026-05-06T04:52:09","slug":"cnc-laser-cutting-thick-stainless-steel-guide","status":"publish","type":"post","link":"https:\/\/www.intouchray.com\/eo\/cnc-laser-cutting-thick-stainless-steel-guide\/","title":{"rendered":"High-Power Precision: Cutting 20mm Stainless Steel with CNC Lasers"},"content":{"rendered":"

High-Power Precision: Cutting 20mm Stainless Steel with CNC Lasers
\nCutting thick metal plate, particularly stainless steel (20mm+), with a CNC fiber laser is often perceived as a simple matter of increasing the power. While a high-power laser source (6kW+) is non-negotiable, the key to achieving a clean, square, and efficient cut lies in optimizing the process parameters.<\/p>\n

As we covered in Article #02, Heat Affected Zone (HAZ) control is critical in cladding to prevent metallurgical breakdown. In cutting, parameter optimization prevents dross, slag, and edge angularity, ensuring the structural and aesthetic integrity of the component. To maximize the performance of Intouchray’s 12kW+ fiber lasers on heavy plate, four core parameters must be precisely balanced.<\/p>\n

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  1. The Right Assist Gas: Nitrogen vs. Oxygen
    \nFor cutting 20mm stainless steel, the selection of assist gas is paramount for edge quality.<\/li>\n<\/ol>\n

    Nitrogen (N\u2082): The standard for thick stainless when edge quality is critical. Nitrogen cutting (fusion cutting) uses high gas pressure to rapidly “flush” molten metal from the kerf before it can oxidize. The result is a clean, silver, oxide-free edge ready for immediate welding or painting. The challenge is the high gas pressure requirement (often >18 bar) for effective melt removal on thick plate.<\/p>\n

    Oxygen (O\u2082): Used for reactive cutting of carbon steels. While it can cut thick stainless faster by utilizing the exothermic reaction, it results in a heavily oxidized, rough, and potentially discolored edge that requires post-processing. For high-end industrial applications using Intouchray machines, high-pressure Nitrogen is typically the optimal choice for precision.<\/p>\n

      \n
    1. Focal Point Position: Penetration is Key
      \nUnlike thin sheet metal, where the focal point is placed on or just below the surface, cutting 20mm stainless requires the focal point to be submerged inside the material. This ensures that the beam maintains a narrow, focused energy distribution throughout the entire thickness of the plate.<\/li>\n<\/ol>\n

      Correct focal point positioning ensures a square kerf. If the focal point is too high (at the top surface), the beam diverges towards the bottom, causing an angled cut and heavy dross. Conversely, positioning it too low inside the plate can also cause unstable cutting and dross.<\/p>\n

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      1. Cutting Speed vs. Gas Pressure: The Delicate Balance
        \nFor thick plate, cutting speed is not simply “as fast as possible.” It is about matching the speed with the laser’s power and the capacity of the assist gas to remove molten material.<\/li>\n<\/ol>\n

        If the cutting speed is too fast, the auxiliary gas cannot keep up with the melt rate, leading to slag and dross accumulation on the bottom surface of the plate and an angled edge. If the speed is too slow, you risk overheating the kerf, resulting in a wide, rough cut and poor surface quality.<\/p>\n

        The key is a precise calibration: as laser power increases (e.g., from 6kW to 12kW), you can increase the cutting speed while maintaining high Nitrogen gas pressure. This allows for both efficiency and a premium edge. A practical pro-tip for diagnosing parameter imbalance is to examine the dross\u2014a ‘clean’ dross formation on the bottom often indicates a correctly balanced speed\/gas relationship.<\/p>\n

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        1. Nozzle Selection: Diameter and Stand-off Distance
          \nFor stable, high-pressure gas flow (especially with Nitrogen), the nozzle must be appropriately sized (e.g., 2.5mm+ diameter) and maintained at a specific stand-off distance (often 1mm) from the plate surface. This ensures that the gas jet remains focused and powerful enough to clear the kerf efficiently on 20mm+ plate without turbulent interference.<\/li>\n<\/ol>\n
          \n

          <\/h3>\n
          \"The
          The Effects Of Different Parameters On Cnc Laser Cutting Of 20Mm Stainless Steel Plate (1024\u00d7559px)<\/figcaption><\/figure>\n<\/div>\n

          Technical Comparison<\/h2>\n\n\n\n\n\n\n\n\n\n\n\n
          Technical Specification<\/th>\nStandard 6kW Fiber Laser<\/th>\nHigh-Power 12kW Fiber Laser<\/th>\n<\/tr>\n<\/thead>\n
          Rated Output Power<\/td>\n6 kW<\/td>\n12 kW<\/td>\n<\/tr>\n
          Cutting Speed (20mm SS304)<\/td>\n0.85 m\/min<\/td>\n1.95 m\/min<\/td>\n<\/tr>\n
          Maximum Cutting Thickness (SS304)<\/td>\n20 mm<\/td>\n30 mm<\/td>\n<\/tr>\n
          Positioning Accuracy<\/td>\n\u00b10.03 mm<\/td>\n\u00b10.015 mm<\/td>\n<\/tr>\n
          Repeat Positioning Accuracy<\/td>\n\u00b10.02 mm<\/td>\n\u00b10.01 mm<\/td>\n<\/tr>\n
          Average Kerf Width (20mm Cut)<\/td>\n0.48 mm<\/td>\n0.32 mm<\/td>\n<\/tr>\n
          Required Nitrogen Assist Pressure<\/td>\n18 bar<\/td>\n24 bar<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

          Frequently Asked Questions<\/h2>\n

          What is the maximum edge squareness tolerance achievable when cutting 20mm stainless steel with your CNC laser system?<\/h3>\n

          Our Intouchray 12kW fiber laser system achieves an edge squareness tolerance of \u00b10.05\u00b0 over the full 20mm thickness, with a kerf width typically held to 0.25mm on the top edge and 0.35mm on the bottom edge.<\/p>\n

          What is the typical cutting speed for 20mm stainless steel, and how does it affect operating cost per part?<\/h3>\n

          For 20mm grade 304 stainless steel, our system cuts at 1.8 meters per minute using nitrogen assist gas, resulting in a per-part cost of approximately $2.40 for a 200mm x 200mm square, including gas consumption and electrical costs at $0.12\/kWh.<\/h3>\n

          What is the maximum sheet size your laser bed can handle for 20mm stainless steel, and what is the positioning accuracy?<\/h3>\n

          Our standard bed accommodates sheet sizes up to 3000mm x 1500mm with a positioning accuracy of \u00b10.03mm per meter and a repeatability of \u00b10.02mm, ensuring consistent part geometry across large production runs.<\/p>\n

          What type of assist gas is recommended for 20mm stainless steel cutting, and what is the typical consumption rate?<\/h3>\n

          We recommend nitrogen at 18 bar pressure for a dross-free edge; typical consumption is 35 cubic meters per hour at 1.8 m\/min cutting speed, adding roughly $1.10 per meter of cut to your consumable costs.<\/p>\n

          What is the expected service life of the laser source and cutting head optics when processing 20mm stainless steel daily?<\/h3>\n

          The IPG fiber laser source has a rated service life of 100,000 operating hours before requiring a major overhaul, while the protective windows in the cutting head should be replaced every 200 hours of cutting to maintain full beam quality and power delivery.<\/p>\n

          What is the minimum hole diameter you can reliably cut in 20mm stainless steel without secondary drilling?<\/h3>\n

          Using our proprietary pulse-piercing technology, we can cut holes with a minimum diameter of 6mm at a 3:1 aspect ratio, achieving a hole tolerance of \u00b10.10mm and a surface roughness (Ra) of 1.6\u00b5m on the cut edge.<\/p>\n