Choose a power tier first
Start with a tier, then validate with sample cutting using your own material grade and edge-quality requirement. These are practical “most-common” ranges for industrial sheet cutting.
3–6 kW
Best for thin-to-medium mix where most work is ≤ 6–10 mm and you want efficient running costs. Great for general fabrication, HVAC, enclosures, and daily stainless/aluminum up to moderate thickness.
8–12 kW
The “productivity” tier. Targets higher throughput and cleaner nitrogen edges on thicker stainless/aluminum (where 6 kW slows down). Often the sweet spot for job shops wanting speed without extreme utilities.
15–20 kW
For heavy plate workflow or high-volume stainless/aluminum where cycle time dominates. Useful when thickness regularly sits in the 12–25+ mm zone and edge quality must stay consistent.
30 kW+
Specialized high-throughput / heavy plate environments. Requires stronger site utilities, process control, and real nesting volume to justify.
Choose the lowest power tier that reliably hits your required edge quality at your typical thickness (not your rare maximum). If the edge spec is nitrogen-clean on stainless/aluminum and you care about speed, you often move up a tier faster than you expect.
Video: GA Series Power Selection Walkthrough
Watch the quick overview, then use the power-tier selector and validation checklist below.
The 3 variables that actually matter
A. Material & reflectivity / thermal behavior
Stainless, aluminum, brass, and copper behave differently under the beam. For many shops, the key takeaway is: the same thickness does not require the same power when you switch material, gas strategy, and required edge appearance.
- Carbon steel (CS): oxygen cutting is “forgiving” on maximum thickness, but edge oxidation and heat-affected color may be unacceptable for some parts.
- Stainless (SS): nitrogen cutting protects edge color and cleanliness, but high-pressure gas and stable melt ejection often push you into higher power for productivity.
- Aluminum: strong thermal conductivity and reflectivity mean process stability and speed benefit more from higher power and correct optics/nozzle strategy.
- Brass / copper: reflective materials can be more sensitive—choose proven process configs and validate with samples.
B. Thickness distribution (your real cut list)
“Max thickness” is a marketing number. Your ROI is driven by where you spend most hours. If 70% of your parts are 2–6 mm, then power should be optimized around that range (speed, pierce reliability, gas cost, part quality).
C. Edge quality requirement (and what “quality” means to you)
Different buyers mean different “quality”: burr limit, taper tolerance, dross cleanup, oxide allowance, heat tint limit, and whether the edge needs to be weld-ready. Power is just one lever—gas, nozzle, focus, head, and machine rigidity all matter.
Are you okay with oxygen-cut carbon steel edges (oxidized, some roughness) for thicker plate, or do you need nitrogen-clean edges across more of your thickness range? That one answer shifts power tier selection more than anything else.
Oxygen vs nitrogen: edge quality and operating cost
Oxygen cutting (typical for carbon steel)
Pros: can cut thicker CS with lower power; often lower gas pressure; “max thickness” looks impressive.
Tradeoffs: oxide layer, more heat input, sometimes more cleanup; edge may not meet paint/weld/appearance specs without extra steps.
Nitrogen cutting (common for SS/aluminum)
Pros: clean, bright edges; minimal oxidation; often better downstream welding/finishing.
Tradeoffs: higher gas pressure and consumption; thicker SS/Al can become power-hungry if you want speed + consistency.
If your business needs “finished-looking” edges straight off the machine, you typically prioritize nitrogen strategy— which often pushes you toward higher power tiers to maintain throughput at thicker gauges.
In many real shops, assist gas strategy dominates hourly cost more than electricity. Don’t pick power in isolation—model it with your gas plan and your edge requirement.
Practical power-by-material matrix (what most buyers mean by “enough”)
This matrix is a selection starting point (not a guarantee). Your exact results depend on material grade, nozzle/focus, gas purity & pressure, and parameter tuning. Use it to shortlist tiers, then confirm with sample cutting.
| Material / Edge expectation | Most work ≤ 6 mm | Typical 6–12 mm | Typical 12–20 mm | Typical 20–30 mm | Notes |
|---|---|---|---|---|---|
|
Carbon steel (oxygen) Oxidized edge OK Value-oriented |
3–6 kW | 6–8 kW | 8–12 kW | 12–20 kW | Oxygen helps max thickness at lower kW, but edge appearance differs from nitrogen cuts. |
|
Carbon steel (nitrogen) Cleaner edge Less oxidation |
6–8 kW | 8–12 kW | 12–20 kW | 20 kW+ | If you require nitrogen-clean CS edges, power tier usually jumps vs oxygen cutting. |
|
Stainless (nitrogen) Bright edge Low heat tint |
3–6 kW | 6–12 kW | 12–20 kW | 20 kW+ | For SS, buyers often upgrade power to keep speed stable as thickness rises. |
|
Aluminum (nitrogen) Stable process Speed-focused |
6 kW | 8–12 kW | 12–20 kW | 20 kW+ | Aluminum often benefits from higher power + proven optics/nozzle strategy for consistency. |
|
Brass / copper Reflective Validate samples |
6–12 kW | 8–20 kW | 12–30 kW+ | — | Highly application-dependent. Confirm feasibility and parameter stability with your real material. |
Why the ranges overlap: “Enough power” depends on whether you prioritize max thickness capability, edge finish, or cycle time. If you’re a job shop, power is often chosen to protect throughput on the thicker half of your workload.
GA Series: common power ranges and who they fit
GA Series is an enclosed, exchange-table platform—so the machine workflow often supports higher utilization. That means power choice should match not just “can it cut,” but how many hours you will actually run and how fast you need to clear jobs.
Typical GA buyer profiles
- 3–6 kW GA: thin-to-medium mix, high versatility, controlled operating cost; strong default when most work is ≤ 6–10 mm and edge spec is reasonable.
- 8–12 kW GA: production job shops needing faster SS/Al nitrogen cutting and better throughput on thicker gauges.
- 15–20 kW+ GA: heavy plate and high-volume environments where time per part dominates and utilities are planned accordingly.
If your stainless/aluminum jobs frequently sit in the “slow zone” on 6 kW (because you demand clean nitrogen edges), moving to 12 kW is often the most noticeable real-world productivity jump—especially when your exchange-table workflow keeps the machine fed.
Next step: combine this with bed size selection so your material handling matches your power choice: Fiber laser cutting bed size (3015/4020/6025/8025).
ROI checklist: avoid wrong assumptions
ROI differs drastically between oxygen-cut carbon steel vs nitrogen-cut stainless/aluminum because gas strategy can dominate hourly cost. Build your ROI model around your actual mix, then validate with sample cutting and a real nesting plan.
- Define your thickness distribution (not just “max thickness”). List the top 10 thicknesses by hours.
- Define edge requirements (oxide allowed? burr limit? heat tint limit? weld-ready?).
- Decide gas strategy per material/thickness (oxygen vs nitrogen; purity/pressure plan).
- Estimate effective cutting hours: enclosure + exchange table reduces waiting—if your upstream/downstream workflow supports it.
- Test cut critical parts (the thicknesses that decide your tier). Confirm pierce success, taper, dross, speed stability.
- Confirm utilities & site prep: power tier is meaningless if gas/air/extraction is undersized.
Configuration notes that affect cut results (even at the same kW)
Two machines with the same power can produce different results depending on process control and supporting components. If you want power selection to translate into real edge quality, align these items early.
Cutting head & sensing
Height control stability, piercing strategy, and focusing consistency matter for burr/taper and repeatability—especially at thicker gauges.
Nozzles, optics, and parameter library
Your “process window” depends heavily on nozzle type, clean optics, and a tuned parameter set for your material grade and gas strategy.
Assist gas delivery
Pressure stability, purity, and flow capacity decide edge brightness and dross behavior on nitrogen cutting.
Machine rigidity & thermal control
Stable motion + good thermal management helps maintain quality at high speed and long runs.
If your selection goal is “clean edges with minimal rework,” treat power as part of a system—not a single spec. For a complete GA purchasing workflow, refer back to the pillar guide: GA Series selection & configuration guide.
FAQ: Fiber laser power selection
Is higher laser power always better?
Not always. Higher power improves speed and expands your stable process window at thicker gauges, but it can increase utilities requirements and may not improve ROI if most of your hours are on thin sheet. Choose the lowest tier that reliably hits your required edge quality at your typical thickness.
Why does nitrogen cutting often push buyers to higher power?
Nitrogen cutting aims for cleaner, brighter edges with less oxidation. Maintaining stable melt ejection and high speed at thicker stainless/aluminum typically benefits from higher power and strong gas delivery.
Can a lower-power laser cut thick carbon steel?
With oxygen cutting, lower power can cut surprisingly thick carbon steel, but the tradeoff is often slower speed, more heat input, and an oxidized edge. If you need cleaner edges or higher throughput, moving up a power tier is common.
What should I prioritize: max thickness or throughput?
Throughput usually drives ROI. “Max thickness” is often a rare job. Build your selection around the thicknesses that consume most cutting hours and the edge spec you must consistently deliver.
Does power selection change when I switch from stainless to aluminum?
Often yes. Aluminum’s thermal behavior and reflectivity can benefit from higher power and proven process configuration for stable, clean cutting—especially if you want speed and consistency across a broader thickness range.
What else affects edge quality besides power?
Assist gas pressure/purity, nozzle and focus setup, cutting head sensing/control, parameter tuning, and machine stability all influence burr, taper, dross, and heat tint. That’s why sample cutting is essential before finalizing power.
How do I validate power choice quickly?
Test cut your “decision thicknesses” (the ones that make you consider upgrading power). Confirm pierce success, speed stability, burr/taper limits, and whether the edge meets your downstream finishing/welding needs.
Should I decide bed size first or power first?
Do them together. Bed size affects handling flow and utilization; power affects throughput and cut quality. Your best setup is the combination that matches your sheet format, part mix, and edge requirements.
