20kW Fiber Laser Cutting Chart: Thickness and Speed

In short: A 20kW fiber laser cutting chart gives cutting speed by thickness, material and assist gas.

Two published charts agree on about 2.7–3.2 m/min for 20 mm carbon steel cut with nitrogen or air. These are manufacturer-published figures, not our test results. Ten of the 13 rows we compared agree within about 11 %, and three differ by 27 % to 58 %.

How to read a 20kW cutting chart

A cutting chart is a table of recommended settings published by a builder or dealer. Each row repeats the same columns, and the speed means nothing without the rest of the row:

Thickness (mm) and speed (m/min). The straight-line cutting feed at the stated settings.
Laser power (W). In chart A, nitrogen and air rows use the full 20,000 W. Its oxygen rows for 10 to 20 mm carbon steel use only 6,000 to 12,000 W, and full power from 22 mm up (source 1).
Gas and pressure (bar). Chart A lists oxygen at 0.6 to 1.8 bar for carbon steel, and nitrogen or air at 8 to 20 bar (source 1).
Nozzle (mm). Chart A explains the letters: S is single, E is double-layer high-speed, SP is special double-layer, and B is a wide nozzle for thick stainless steel on nitrogen (source 1).
Focus (mm) and cutting height (mm). Chart A: 0 means the focus is on the surface, minus means inside the material (nitrogen cutting of stainless steel and aluminium), plus means above the surface (oxygen cutting of carbon steel), and the thicker the metal, the deeper the offset (source 1).

The 20 kW tables in chart A were made with a 100 µm fiber core, 100 mm collimation and 200 mm focus (source 1). A different cutting head or laser source changes the settings, so a chart for another setup is a starting point only.

Two published charts, side by side

We opened two public 20kW charts on 2 November 2026. Chart A is from SBM Laser, a seller and service company for laser cutting machines (source 1). Chart B is from AccTek Group, a laser cutting machine builder (source 2). Every figure below is theirs, labelled manufacturer-published, not our test. Speeds are in m/min, as published, with ranges where the source gives a range.

Material and gas	Thickness	Chart A speed	Chart B speed	Gap
Carbon steel, N₂ or air	5 mm	25–28	23–28	+4 %
Carbon steel, N₂ or air	10 mm	10–13	9.0–12.0	+10 %
Carbon steel, N₂ or air	20 mm	2.7–3.2	2.7–3.2	0 %
Carbon steel, O₂	10 mm	2.3 (at 6,000 W)	2.0–2.3	+7 %
Carbon steel, O₂	20 mm	1.5 (at 12,000 W)	1.3–1.4	+11 %
Carbon steel, O₂	30 mm	1.2	1.2–1.3	−4 %
Stainless steel, N₂	5 mm	25	22–24	+9 %
Stainless steel, N₂	10 mm	14	10–12	+27 %
Stainless steel, N₂	20 mm	3	3.0–3.2	−3 %
Stainless steel, air	10 mm	13	11–13	+8 %
Aluminium, N₂	5 mm	30	18–20	+58 %
Aluminium, N₂	10 mm	8.5	9.0–10.0	−11 %
Aluminium, N₂	20 mm	2.3	1.5–2.0	+31 %

Manufacturer-published, not our test. Chart A: SBM Laser, 20 kW tables (source 1). Chart B: AccTek Group, 20kW cutting capacity table (source 2); for oxygen rows chart B’s “negative focal” method is used. Gap = chart A minus chart B, relative to chart B, using the midpoint of any range (our calculation). Rows were picked to cover three thicknesses per material, not to show the biggest gaps.

Most rows agree closely. The three that do not are 5 mm aluminium, 20 mm aluminium and 10 mm stainless steel on nitrogen. Neither page says why. It could be test conditions, gas, a different edge-quality target or a typing difference, and we cannot tell which.

The settings behind the speeds are mostly the same in both charts. For 20 mm carbon steel on nitrogen or air, both list a 6 mm nozzle, 10 bar and a focus of −8 mm. We think the two charts probably share an origin, so treat them as one body of data, not as two independent confirmations. That is our inference, not something either page states.

Settings that go with the speeds

Material, thickness and gas	Power (W)	Pressure (bar)	Nozzle (mm)	Focus (mm)	Height (mm)
Carbon steel 10 mm, N₂ or air	20,000	8	3.5S	−1.5	0.5
Carbon steel 20 mm, N₂ or air	20,000	10	6.0S	−8	0.5
Carbon steel 20 mm, O₂	12,000	0.6	1.6E	+12	0.8
Carbon steel 30 mm, O₂	20,000	1.2	1.5SP	+13.5	0.4
Stainless steel 10 mm, N₂	20,000	8	5.0B	−1.5	0.3
Stainless steel 20 mm, N₂	20,000	12	6.0B	−7.5	0.3
Aluminium 10 mm, N₂	20,000	14	3.5S	−5	0.5
Aluminium 20 mm, N₂	20,000	18	6.0B	−7	0.3

Manufacturer-published, not our test. All rows from chart A (SBM Laser, source 1), 100 µm fiber core, 100 mm collimation, 200 mm focus.

Maximum thickness versus quality thickness

Search for “20kW laser cutting thickness” and you get one number. Published figures for the same power class are different kinds of number:

Source	What it states	What kind of number
Charts A and B (sources 1, 2)	Carbon steel to 80 mm with oxygen at 0.12–0.15 m/min. Stainless steel to 100 mm with nitrogen at 0.04–0.05 m/min. Aluminium to 60 mm at 0.2–0.3 m/min.	Parameter rows at the top of the chart. 0.05 m/min is 50 mm per minute, a crawl
A machine builder’s laser-source table, covering 4 to 20 kW (source 3)	Mild steel up to 1.5 in (about 38 mm); stainless steel and aluminium up to 1 in (about 25 mm).	Maximum for the whole source range, not for 20 kW alone
The same builder’s 20 kW option (source 4)	Mild steel “exceeding 50mm”.	Maximum claim
The same builder’s fiber laser page (source 3)	“The cutting quality in mild steel is comparable up to 15 millimeters in thickness.”	Quality statement, not tied to 20 kW
Another machine builder’s 20 kW announcement (source 5)	20 kilowatts “open up extended applications in steel and aluminum of up to 50 mm”.	Maximum claim; the page does not give a date we could read
ISO 9013:2017 (source 6)	Applies to laser cuts from 0.5 mm to 32 mm.	Scope of the edge-quality standard

Manufacturer-published, not our test, except the last row, which is a standard’s catalogue entry.

Read it this way. A maximum thickness is the thickest plate the machine separates at all, usually slowly and without a stated edge class. A quality thickness is the thickness at which the edge meets a stated class at a speed you can run in production. ISO 9013 classifies laser cuts from 0.5 to 32 mm (source 6), so above 32 mm its classes do not apply, and the edge you accept has to be agreed on a test cut. For carbon steel the published maxima for this power class run from about 38 mm to 80 mm, which shows how much the word “maximum” can stretch.

What changes the numbers

Assist gas. In chart A, 10 mm carbon steel runs at 10–13 m/min on nitrogen or air and at 2.3 m/min on oxygen, roughly five times slower (source 1). The same page says oxygen gives a cleaner edge on medium and thick carbon steel, and that at 12–20 kW nitrogen or air is effective up to 10–20 mm (source 1). Nitrogen and air run at 8 bar or more, so gas supply matters: see nitrogen generator vs bulk nitrogen and our guide to assist gas.
The oxygen method. Chart B lists two oxygen methods for 20 mm carbon steel: 1.3–1.4 m/min with its “negative focal” method at 0.6 bar, and 2.8–3.0 m/min with its “positive focal” method at 1.2 bar, both with a 1.6 mm nozzle (source 2). Same gas, same thickness, about twice the speed. The page does not say how the edges compare.
Nozzle and focus. Chart A moves from a 3.0 mm single nozzle at 5 mm to a 6.0 mm one at 20 mm on nitrogen, and the focus sinks from 0 to −8 mm (source 1). Both feed straight into speed and edge quality; our article on nozzles and protective windows covers how wear changes the cut.
Material and condition. Chart A states that real parameters depend on metal quality, steel grade, gas purity, optics condition and cutting head model, and should be adjusted on test cuts (source 1). Neither chart names a steel grade.
Edge-quality target. Neither chart says which ISO 9013 class its speeds reach. A faster setting that leaves dross or taper is not comparable with a slower clean one. See dross and burr troubleshooting.
Heat and cooling. Chart B’s page says the operating environment should stay between about 10 °C and 35 °C, below 70 % humidity without condensation, and warns that excessive heat can overload cooling systems (source 2). Our chiller guide covers the practical side.
Part geometry. A chart gives the speed of a straight cut. Corners, small holes and piercing thick plate take longer, so multiplying chart speed by cut length overstates what a real nest delivers.

How to use a chart when you compare quotations

Ask for the supplier’s chart for the exact laser source, cutting head and gas supply in the offer, with the fiber core, collimation and focal length stated.
Ask what edge class each speed achieves, and under what conditions: gas purity, steel grade, sheet condition.
Compare like with like: same material, thickness, gas, pressure and nozzle type, and check whether each speed uses the full laser power.
Ask separately for the quality thickness and the maximum thickness for each material.
Ask for a test cut on your own material at your thickness, measured against your drawing.

We publish no cutting figures for our own machines until documented test results exist, and the cutting capability page says so. Meanwhile, read how to choose laser power for the step from 12 kW to 20 kW, and thick-plate cutting if your work is above 20 mm.

Frequently asked questions

What thickness can a 20kW fiber laser cut?

Published maximum figures run from about 38 mm to 80 mm for carbon steel and from about 25 mm to 100 mm for stainless steel, with a crawl speed at the top end. Quality cutting is a lower number: ask for the thickness at which your edge class holds.

How fast does a 20kW fiber laser cut 10 mm steel?

Two published charts show 9–13 m/min for 10 mm carbon steel with nitrogen or air at full power, and 2.0–2.3 m/min with oxygen. One chart says oxygen leaves the cleaner edge. These are makers’ figures, not our tests.

Is oxygen or nitrogen better for 20kW cutting?

It depends on thickness and the edge you need. One chart says oxygen gives a cleaner edge on medium and thick carbon steel, while nitrogen or air is effective up to 10–20 mm at 12–20 kW. Nitrogen and air need high pressure and more gas.

Can a 20kW laser cut aluminium?

The two charts list aluminium cut with nitrogen from 1 mm to 60 mm. At 5 mm they differ: 30 m/min in one chart, 18–20 m/min in the other. That gap shows why a test cut on your own material matters.

Are these Halcyon Laser’s cutting speeds?

No. They come from two other companies’ published charts. We publish no cutting figures for our machines until documented test results exist. Send a drawing through the test cut page and we tell you whether a test cut can be arranged.

Next step

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Sources

SBM Laser (SBMachines, a seller and service company for laser cutting machines), “Fiber Laser Cutting Parameters”, 20 kW tables and notes: reference recommendations, page undated — sbmlaser.com (accessed 2026-11-02)
AccTek Group (laser cutting machine builder), “20kW Laser Cutting Machines”: 20kW laser cutting capacity table and operating conditions, page undated — www.acctekgroup.com (accessed 2026-11-02)
Messer Cutting Systems, fiber laser page: laser-source series table (4,000 to 20,000 W) and statement on cutting quality in mild steel; builder’s own claims — us.messer-cutting.com (accessed 2026-11-02)
Messer Cutting Systems, 2–20 kW cutting machines page: 20 kW option “exceeding 50mm mild steel”; builder’s own claim — us.messer-cutting.com (accessed 2026-11-02)
Bystronic, “Laser cutting in the fast lane: the new ByStar Fiber with 20 kilowatts of laser power”: builder’s own claim, news page dated April 2022 — www.bystronic.com (accessed 2026-11-02)
ISO 9013:2017, Thermal cutting: classification of thermal cuts (catalogue entry via Standard Norge): laser cuts from 0,5 mm to 32 mm — online.standard.no (accessed 2026-11-02)

20kW fiber laser cutting chart: thickness and speed