When people shop for a handheld fiber laser system, one of the first questions is: “How thick can it cut?”
In this guide, we use real test data from 800 W and 1200W handheld cutting heads on stainless steel, carbon steel, aluminum and brass. The charts below were measured with nitrogen shielding gas at 6–8 bar and 100 % duty cycle, so they represent realistic values for workshop use — not just theoretical numbers.
With a standard handheld fiber cutting head and 6–8 bar nitrogen, our tests show the following recommended maximum cutting thickness:
-
800W handheld laser
- Stainless steel: up to 3 mm
- Carbon steel: up to 3 mm
- Aluminum: up to 3 mm
- Brass: 1 mm typical, 2 mm as an upper limit with careful tuning
-
1200W handheld laser
- Stainless steel: up to 4 mm
- Carbon steel: up to 4 mm
- Aluminum: up to 4 mm
- Brass: up to 2 mm
1200W Handheld Fiber Laser Cutting Parameters
The table below shows the actual cutting speed, gas and peak power percentage we used for 1200W handheld cutting. These values are a very good starting window for most workshops. Fine-tune slightly for your material batch and surface condition.
| Material | Thickness (mm) | Cutting speed (mm/s) | Gas | Pressure (bar) | Peak power (%) | PWM duty cycle (%) | PWM frequency (Hz) | Scanning frequency (Hz) | Scan width (mm) |
|---|---|---|---|---|---|---|---|---|---|
| Stainless steel | 1.0 | 18 | N2 | 6–8 | 65 | 100 | 1000 | 5 | 0.0 |
| Stainless steel | 2.0 | 12 | N2 | 6–8 | 75 | 100 | 1000 | 5 | 0.0 |
| Stainless steel | 3.0 | 8 | N2 | 6–8 | 85 | 100 | 1000 | 5 | 0.0 |
| Stainless steel | 4.0 | 6 | N2 | 6–8 | 95 | 100 | 1000 | 5 | 0.0 |
| Carbon steel | 1.0 | 18 | N2 | 6–8 | 65 | 100 | 1000 | 5 | 0.0 |
| Carbon steel | 2.0 | 12 | N2 | 6–8 | 75 | 100 | 1000 | 5 | 0.0 |
| Carbon steel | 3.0 | 8 | N2 | 6–8 | 85 | 100 | 1000 | 5 | 0.0 |
| Carbon steel | 4.0 | 6 | N2 | 6–8 | 95 | 100 | 1000 | 5 | 0.0 |
| Aluminum | 1.0 | 18 | N2 | 6–8 | 65 | 100 | 1000 | 5 | 0.0 |
| Aluminum | 2.0 | 12 | N2 | 6–8 | 75 | 100 | 1000 | 5 | 0.0 |
| Aluminum | 3.0 | 8 | N2 | 6–8 | 85 | 100 | 1000 | 5 | 0.0 |
| Aluminum | 4.0 | 6 | N2 | 6–8 | 95 | 100 | 1000 | 5 | 0.0 |
| Brass | 1.0 | 12 | N2 | 6–8 | 75 | 100 | 1000 | 5 | 0.0 |
| Brass | 2.0 | 8 | N2 | 6–8 | 95 | 100 | 1000 | 5 | 0.0 |
800W Handheld Fiber Laser Cutting Parameters
For 800W, the same materials can be cut, but the speed drops and the recommended maximum thickness is slightly lower. That is why 800W handheld systems are ideal for thin-sheet work and repair jobs, while 1200W is better if you regularly work on 3–4 mm plate.
| Material | Thickness (mm) | Cutting speed (mm/s) | Gas | Pressure (bar) | Peak power (%) | PWM duty cycle (%) | PWM frequency (Hz) | Scanning frequency (Hz) | Scan width (mm) |
|---|---|---|---|---|---|---|---|---|---|
| Stainless steel | 1.0 | 12 | N2 | 6–8 | 75 | 100 | 1000 | 5 | 0.0 |
| Stainless steel | 2.0 | 8 | N2 | 6–8 | 85 | 100 | 1000 | 5 | 0.0 |
| Stainless steel | 3.0 | 6 | N2 | 6–8 | 95 | 100 | 1000 | 5 | 0.0 |
| Carbon steel | 1.0 | 12 | N2 | 6–8 | 75 | 100 | 1000 | 5 | 0.0 |
| Carbon steel | 2.0 | 8 | N2 | 6–8 | 85 | 100 | 1000 | 5 | 0.0 |
| Carbon steel | 3.0 | 6 | N2 | 6–8 | 95 | 100 | 1000 | 5 | 0.0 |
| Aluminum | 1.0 | 12 | N2 | 6–8 | 75 | 100 | 1000 | 5 | 0.0 |
| Aluminum | 2.0 | 8 | N2 | 6–8 | 85 | 100 | 1000 | 5 | 0.0 |
| Aluminum | 3.0 | 6 | N2 | 6–8 | 95 | 100 | 1000 | 5 | 0.0 |
| Brass | 1.0 | 8 | N2 | 6–8 | 95 | 100 | 1000 | 5 | 0.0 |
Why Handheld Fiber Lasers Have a Thickness Limit
On paper, you might think a 1200W handheld laser could cut much thicker than 4 mm. In practice, several physical factors define a realistic limit:
Available power vs. material cross-section
As thickness increases, the laser must melt a larger cross-section of metal and push more molten material out of the kerf. At some point, the energy density at the focus is not enough to maintain a stable keyhole and the cut becomes intermittent or stops.
Nitrogen pressure & slag removal
For clean edges on stainless steel and aluminum, nitrogen at 6–8 bar is used to blow molten metal out of the cut. On thicker plates the molten pool becomes deeper and harder to clear, which leads to heavy slag and rough edges even if the laser can technically melt through.
Beam quality & focus stability
Handheld cutting heads are optimized for portability and operator comfort. The optics and wobble mechanics are different from a high-precision cutting head on a gantry machine, so the achievable focus length and spot quality are better suited for thin to medium sheet.
Human factor: hand motion
On a CNC table, the beam follows a perfectly smooth path. In handheld cutting, natural hand motion and changes in stand-off distance introduce variation. For 1–4 mm plate this is acceptable; on thicker material it quickly leads to uneven edges or incomplete cutting.
Recommended Thickness by Material
Based on the test data above, here is a simple decision chart you can use when planning jobs:
| Material | 800W handheld | 1200W handheld | Notes |
|---|---|---|---|
| Stainless steel | 1–3 mm | 1–4 mm | Use N2 for bright edges and corrosion resistance. |
| Carbon steel | 1–3 mm | 1–4 mm | N2 gives clean edges; O2 can be used for faster but oxidized cuts. |
| Aluminum | Up to 3 mm | Up to 4 mm | High reflectivity requires careful focus and surface cleaning. |
| Brass | 1 mm typical | 1–2 mm | Most challenging to cut; keep lenses well protected against back reflection. |
800W vs 1200W: Which Power Should You Choose?
Both power levels have a place in real workshops. The right choice depends on the type of jobs you run most often.
When 800W handheld is enough
- Mainly cutting 1–2 mm stainless or carbon steel
- On-site repair work, pipe modification, dismantling old structures
- Shops where cutting speed is less important than portability and cost
When you should choose 1200W
- Regular cutting of 3–4 mm sheet in stainless, carbon steel, or aluminum
- Higher productivity is required (more parts per hour)
- You plan to pair handheld cutting with laser welding and surface cleaning
FAQ
Q1. Can an 800W handheld laser cut 5 mm stainless steel?
In theory, you may be able to pierce and cut at a very low speed, but the process will not be stable or efficient. For consistent quality, we recommend limiting 800 W handheld systems to around 3 mm stainless steel. Thicker plates should be cut on a dedicated fiber laser cutting machine.
Q2. Can I use compressed air instead of nitrogen?
Compressed air can be used on carbon steel and aluminum when edge color is not critical. However, for stainless steel and for the best cosmetic finish, nitrogen is strongly recommended. The data in this article is based on N2 at 6–8 bar.
Q3. Do I need a CNC table for these thicknesses?
No. The parameters here are specifically measured for handheld heads. For repeated parts and higher precision, combining a handheld source with a simple jig or rail can help, but a full CNC machine is only needed when you move to thicker plates or high-volume production.
Q4. What happens if I exceed the recommended thickness?
You will see slow piercing, incomplete cuts, heavy slag and inconsistent edge quality. Operators also have to move much more slowly, which increases heat input and distortion. At that point, it is more economical to use a plate cutting machine.
Q5. Is handheld cutting a replacement for a fiber cutting machine?
No. Handheld systems are perfect for installation work, field repair, trimming and modification of parts. For constant production of parts from sheet or plate, a gantry-style fiber cutting machine is the right choice.
Ready to test your own parts?
Send us your material thickness and drawings and we will run a free sample with our 800 W and 1200 W handheld systems. You will receive cutting videos, edge photos and recommended process parameters tailored to your application.
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