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Views: 0 Author: SMARTECH-Sini Publish Time: 2026-11-12 Origin: Site
In fiber laser cutting, many people assume that if a laser cutting machine can process thick metal plates, it should also be capable of cutting small holes with ease.
However, the reality is quite different.
In many metal fabrication applications, cutting small holes can be more challenging than cutting straight lines or larger contours. Even with a high-power fiber laser cutting machine, problems such as hole deformation, rough edges, burrs, excessive dross, and inaccurate diameters may occur.
So, why can such a seemingly simple task become a challenge in laser cutting?
Let's explore the main reasons behind this phenomenon.
Fiber laser cutting works by focusing a high-energy laser beam onto a metal surface, melting or vaporizing the material locally. Assist gas then removes the molten metal from the cutting area, forming a clean cut.
When cutting large contours, the laser head usually follows a relatively long cutting path, allowing heat to dissipate as the cutting process progresses.
Small holes are different.
Because the cutting area is limited, the laser head must complete the entire cutting path within a relatively small space. Heat can accumulate around the hole, potentially causing excessive melting and thermal deformation.
This may lead to several problems:
Excessive melting along the hole edges.
Local deformation of the metal material.
Increased surface roughness.
Deviations between the actual hole diameter and the designed dimensions.
For thin metal sheets, heat accumulation may cause the hole edges to become distorted. For thicker materials, it can also make molten metal removal more difficult.
Hole diameter is not the only factor that determines cutting difficulty. Material thickness also plays an important role.
For example, consider cutting a 10 mm diameter hole in different thicknesses of steel under otherwise comparable processing conditions:
3 mm steel plate: The laser can generally complete the cutting process relatively easily.
10 mm steel plate: Molten metal must travel through a longer cutting channel, making removal more difficult.
Thicker steel plates: Higher demands are placed on laser power, focal position, cutting speed, and assist gas conditions.
This is why the maximum cutting thickness of a laser machine alone cannot determine its ability to produce high-quality small holes.
In practical applications, the hole-to-thickness ratio is an important reference when evaluating small-hole cutting performance.
Generally, the smaller the hole diameter and the thicker the material, the more challenging the cutting process becomes.
Assist gas plays an essential role in laser cutting.
It helps remove molten metal from the cutting area and directly affects cutting quality and processing efficiency.
When cutting large contours, molten metal usually has more space to escape.
However, during small-hole cutting, the limited space makes it more difficult for molten material and metal spatter to escape efficiently.
If the assist gas pressure, nozzle condition, or cutting parameters are not properly adjusted, several defects may occur:
Dross accumulation at the bottom of the hole.
Burr formation along the cutting edges.
Uneven cutting marks inside the hole.
Inconsistent cutting quality.
Therefore, successful small-hole cutting requires not only sufficient laser energy but also appropriate gas pressure and effective molten-metal removal.
Before cutting a hole, the laser usually needs to pierce through the metal material. This initial process is known as laser piercing.
After piercing, the laser head follows the programmed cutting path to complete the hole.
If the piercing process is not properly controlled, excessive molten metal and spatter may be generated, affecting the quality of the subsequent cutting process.
Cutting speed is another important factor.
Since small holes have relatively short cutting paths, the laser head needs to change direction and speed within a limited area.
If the cutting speed is too high, the material may not be completely cut through.
If the cutting speed is too low, excessive heat may accumulate, resulting in over-melting and distorted edges.
To achieve better results, cutting parameters should be adjusted according to material type, plate thickness, and hole diameter.
For certain applications, specialized small-hole cutting techniques and optimized toolpaths can also help improve processing quality.
Achieving accurate hole dimensions and smooth edges requires careful control of several processing factors.
During the design stage, consider the relationship between hole diameter and material thickness.
Avoid designing holes that are too small for the selected material and processing conditions without first verifying the machine's actual cutting capability.
Adjust laser power, cutting speed, focal position, and piercing parameters according to the material and thickness.
Proper parameter settings help prevent excessive heat concentration and incomplete cutting.
Oxygen and nitrogen are commonly used in fiber laser cutting, depending on the material and desired cutting results.
Selecting the appropriate gas and maintaining suitable pressure helps ensure efficient molten-metal removal.
A damaged, misaligned, or contaminated nozzle can affect gas flow stability and negatively influence cutting quality.
Regular inspection and maintenance of the cutting head and nozzle are important for consistent small-hole cutting performance.
Different laser sources, cutting heads, motion systems, and control software may produce different processing results.
For manufacturers with precision hole-cutting requirements, it is recommended to conduct cutting tests using actual materials and design drawings before purchasing equipment.
Laser cutting does not mean that every shape can be processed with the same level of difficulty.
Compared with ordinary contours, small-hole cutting places higher demands on heat control, molten-metal removal, piercing techniques, and the coordination of the machine's motion system.
This is particularly important in thick-plate processing and precision metal fabrication, where actual small-hole cutting performance can be more meaningful than the maximum cutting thickness alone.
When selecting a fiber laser cutting machine, buyers should consider not only laser power and maximum cutting thickness but also achievable hole diameters, dimensional accuracy, and cutting-edge quality.
The true performance of a laser cutting machine is not measured only by how thick a metal plate it can cut, but also by how accurately and consistently it can process intricate details.
