Application and capacity
Define material, geometry, thickness or capacity, production volume, quality, workflow, and future work.
Fiber laser planning
What Size Fiber Laser Do I Need?
Compare fiber laser power classes using material, thickness, production volume, assist gas, facility power and future work.
Fiber-laser power is only one part of machine sizing. Start with the parts you need to produce, then validate the complete machine configuration around them.
Define the application
- Material grades and the normal—not occasional—thickness range
- Sheet size, part geometry, holes, pierces, and edge acceptance
- Annual volume, shifts, target cycle time, and automation needs
- Assist-gas strategy, electrical service, extraction, air, and floor space
- Software workflow, operator skill, service, and delivered budget
Why more power is not automatically better
Higher power can improve capability in the right process window, but it can also change gas demand, utilities, optics, safety planning, and project cost. A lower-power system may be the better production fit when the material mix and throughput target do not justify the added capacity.
Use representative parts
Send DXF files or drawings, material and thickness, quantities, and the desired finish. Ask for a sample cut or application review before treating any generic capability chart as a purchase decision.
Planning pathway
Connect the requirement to the complete machine project
Machine and facility
Compare configuration, controller, options, utilities, extraction, footprint, access, unloading, and placement.
Ownership and support
Confirm price path, delivery, startup, training, warranty, service, parts, financing, rental, used, or trade-in options.
Next step
Continue with the correct project pathway
Fiber Laser Wattage Selector
Answer seven questions and get a power class, the range the published cutting charts actually claim at that power, whether your shop’s electrical service can feed it, and how much floor space it needs.
What you cut
Thickest material you cut regularly
0.250 in (6.35 mm)
Thinnest material you cut regularly
0.036 in (0.91 mm)
How you run
US service only. Every figure on this page assumes 60 Hz US shop power at 208 V, 240 V or 480 V. If a vendor quotes 380 V or 50 Hz, that is a non-US specification and the machine needs a transformer or a different source to run in a US building.
Recommended power class
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Electrical service check
Floor space estimate
- Machine footprint (approx.)—
- Room needed with 3 ft clearance all sides—
Notes for your situation
What the published charts say at this power class
No single figure is authoritative. The published charts disagree with each other — at 6 kW on mild steel the spread between the lowest and highest published maximum is about 50 %. That is not a rounding difference; it is different assumptions about gas, nozzle, edge quality and what “can cut” means. So here is the whole spread rather than one number.
| Published by | Power | Mild steel | Stainless | Aluminum |
|---|
MachineMFG and SENFENG publish in millimeters; the inch figures in their rows are UmproTech conversions. Southern Fabricating publishes in imperial; the millimeter figures in its rows are UmproTech conversions. MachineMFG’s mild steel figures assume oxygen assist; its stainless and aluminum figures assume nitrogen.
How this recommendation is derived
Step 1 — thickness sets the floor. Your thickest regular material is matched against Southern Fabricating’s imperial chart, because it is a US source publishing in the units US buyers specify in:
- 1.5 kW — 1/4 in mild steel, 16 ga stainless, 0.090 in aluminum
- 2 kW — 3/8 in mild steel, 11 ga stainless, 5/32 in aluminum
- 3 kW — 1/2 in mild steel, 1/4 in stainless, 3/16 in aluminum
- 6 kW and up — 1 in mild steel, 5/8 in stainless, 1/2 in aluminum
Step 2 — volume and edge quality can move it up by one class, and only one. 10–30 sheets a day, continuous production, or a no-secondary-operations edge requirement on stainless or aluminum each add a class. The total bump is capped at one class, because past that point the thing limiting your output is nesting, load/unload automation and gas strategy — not wattage. Buying two classes up on a volume argument alone is how shops end up with a machine they cannot feed.
Step 3 — the electrical check. Published service requirements from Hytek Tools: 1000 W needs single phase 220 V at 50 A; 1500 W single phase 220 V at 60 A; 2000 W three phase at 50 A; 3000 W three phase at 60 A; 4000 W three phase at 70 A; 6000 W three phase at 95 A; 12000 W three phase 480–600 V at 120 A. Above 1.5 kW the machine needs three phase. This is the single most common late discovery in a fiber laser purchase.
US conditions assumed throughout. Every electrical figure on this page is read against 60 Hz US service — 208 V or 240 V single or three phase, or 480 V three phase. Hytek’s “220 V” is a nominal figure; a US building supplies 208 V or 240 V and either satisfies it. Many overseas machine datasheets are written for 380 V at 50 Hz, which does not exist in a US facility — a machine specified that way needs a transformer, and in some cases a different source, before it will run here. Get the input voltage, phase and frequency in writing on the quote.
Step 4 — the footprint. Hytek’s rule of thumb: machine footprint is roughly bed width plus 36 in, and bed length plus 1.5 ft. Arcus CNC publishes a minimum of 3 ft of clearance on all sides for service access. Both are added into the room figure above.
What this does not do. It does not pick a machine, a brand or a configuration, and it does not know your part mix, your nesting efficiency or your material certs. It narrows the field so the conversation starts in the right place.
Where more power does not help
The wattage number is the easiest thing to compare, which is why it gets oversold. On thin-to-mid carbon steel — the work most US job shops actually run — going from 3 kW to 6 kW changes cutting speed surprisingly little. Piercing and edge quality are limited by the gas, the nozzle and the machine dynamics long before they are limited by available power.
Where the extra power does pay back:
- Stainless and aluminum with nitrogen. Higher power buys real speed on nitrogen cuts, and nitrogen is the expensive gas — so it converts directly into gas cost per part.
- Thick-plate piercing. Pierce time on heavy plate is a large share of cycle time on parts with many holes. This is where big power classes visibly separate.
- Reflective material. Copper and brass need power headroom as well as back-reflection protection.
This framing is drawn from practitioner discussion of the 3 kW-versus-6 kW decision at CNC Arena, where working fabricators make this point repeatedly against the marketing charts.
Fiber laser cutting thickness by wattage — what four published charts claim
| Power | Mild / carbon steel | Stainless | Aluminum |
|---|---|---|---|
| MachineMFG — mild steel with oxygen, stainless and aluminum with nitrogen | |||
| 1 kW | 0.24 in (6 mm) | 0.12 in (3 mm) | 0.08 in (2 mm) |
| 1.5 kW | 0.31 in (8 mm) | 0.16 in (4 mm) | 0.16 in (4 mm) |
| 2 kW | 0.39 in (10 mm) | 0.20 in (5 mm) | 0.20 in (5 mm) |
| 3 kW | 0.47 in (12 mm) | 0.31 in (8 mm) | 0.31 in (8 mm) |
| 6 kW | 0.79 in (20 mm) | 0.55 in (14 mm) | 0.63 in (16 mm) |
| 12 kW | 0.87 in (22 mm) | 0.79 in (20 mm) | 0.98 in (25 mm) |
| Southern Fabricating — US dealer, published in imperial | |||
| 1.5 kW | 1/4 in (6.4 mm) | 16 ga — 0.060 in (1.5 mm) | 0.090 in (2.3 mm) |
| 2 kW | 3/8 in (9.5 mm) | 11 ga — 0.120 in (3.0 mm) | 5/32 in (4.0 mm) |
| 3 kW | 1/2 in (12.7 mm) | 1/4 in (6.4 mm) | 3/16 in (4.8 mm) |
| 6 kW and up | 1 in (25.4 mm) | 5/8 in (15.9 mm) | 1/2 in (12.7 mm) |
| SENFENG | |||
| 3 kW | 0.79 in (20 mm) | 0.47 in (12 mm) | 0.24 in (6 mm) |
| 6 kW | 1.18 in (30 mm) | 0.79 in (20 mm) | 0.47 in (12 mm) |
Read the 3 kW and 6 kW rows against each other. At 3 kW on mild steel the published maxima run from 0.47 in to 0.79 in. At 6 kW they run from 0.79 in to 1.18 in — a 50 % spread on the same wattage and the same material. On aluminum at 3 kW the spread is wider still, from 3/16 in to 0.31 in. A published maximum is the thickest a machine will sever under favorable conditions, not the thickest it will cut all day to a saleable edge. Ask any vendor which of those two they are quoting.
Published electrical service requirements
| Laser power | Phase | Voltage | Service |
|---|---|---|---|
| 1000 W | Single phase | 220 V | 50 A |
| 1500 W | Single phase | 220 V | 60 A |
| 2000 W | Three phase | — | 50 A |
| 3000 W | Three phase | — | 60 A |
| 4000 W | Three phase | — | 70 A |
| 6000 W | Three phase | — | 95 A |
| 12000 W | Three phase | 480–600 V | 120 A |
If your building has single phase only, everything from 2 kW up needs either a utility three-phase service upgrade or a rotary or static phase converter sized for the machine. Both are real projects with real lead times, and both are cheaper to discover now than after the machine ships.
Check the frequency and the voltage, not just the phase. These figures are for 60 Hz US service. A datasheet quoting 380 V / 50 Hz is written for a non-US grid and cannot be connected as-is in a US building. Provide total connected load only from the exact quotation and installation package, including machine, source, chiller, extraction and compressor where supplied The exact quotation and installation package must state input voltage, phase, frequency, full-load current, breaker recommendation and whether a transformer is included, separate or buyer-supplied
Sources and attribution
- Cutting thickness and speed by wattage (metric) — MachineMFG, Laser cutting thickness and speed chart
- Imperial cutting capacity by wattage — Southern Fabricating Machinery Sales, Factors to consider buying a fiber laser machine
- 3 kW / 6 kW / 12 kW capability — SENFENG, 3kW, 6kW, 12kW fiber laser cutter — which is right for you
- Electrical service requirements and the footprint rule of thumb — Hytek Tools, Fiber laser FAQ
- Installation clearance requirements — Arcus CNC, Laser cutter installation
- Practitioner discussion of the 3 kW vs 6 kW decision — CNC Arena forum thread
Results are estimates for planning. Published cutting charts describe favorable conditions and vary between manufacturers; final machine, power and gas specification requires a quote review against your part drawings, material certificates and electrical service.