What Is Laser Cutting? How It Works, Types and Uses

By Leon Xu, Engineer, Tuowei Precision · November 2026

Laser cutting is a thermal cutting process that uses a focused, high-power laser beam to melt, burn or vaporize material along a programmed path, while a jet of gas clears the molten material out of the cut. It is the standard way to cut flat sheet metal parts, from thin stainless brackets to carbon steel plate around 25 mm thick.

So what is laser cutting best at, and where does it fall short? This guide answers both.

Short answer: A laser cutter concentrates light from a fiber or CO2 source into a spot a fraction of a millimeter wide. CNC motion moves that spot along the part outline, the beam melts the material, and assist gas such as oxygen, nitrogen or air blows it out of the cut. The result is a clean, narrow cut with no tool contact.

Below we cover how the process works step by step, the three main laser types, which materials cut well, what accuracy to expect, what the process is used for, and the design mistakes that cause most rejected parts.

What Is Laser Cutting?

Laser is an acronym for Light Amplification by Stimulated Emission of Radiation. A laser source produces a beam of light that is a single wavelength and travels in step, which means it can be focused to an extremely small, intense spot. Put enough power into that spot and it heats metal past its melting point almost instantly.

A laser cutting machine is a CNC machine. Computer numerical control moves the cutting head, or the sheet, along a path generated from your CAD file. Because nothing touches the part, there is no tool wear and no cutting force, so thin and delicate parts cut as cleanly as heavy ones.

Key Terms: Kerf, Assist Gas, Piercing and HAZ

A few terms come up again and again:

• Kerf is the width of material the beam removes. On our machines it is about 0.5 mm (0.02 in), and on thin material it can be much narrower.
• Assist gas is the gas blown through the nozzle with the beam to eject molten material and protect the lens.
• Piercing is the first burn through the sheet when a cut starts away from the edge.
• Heat-affected zone (HAZ) is the thin band of material next to the cut whose structure has been changed by heat.

How Does Laser Cutting Work? Step by Step

Here is how laser cutting works on a typical sheet metal job, from file to finished blank:

• Prepare the file. A 2D DXF or a flattened 3D model is loaded into CAM software, which nests parts on the sheet and sets power, speed, focus and gas for the material and thickness.
• Generate the beam. The laser source creates the beam. Fiber lasers carry it to the cutting head through a fiber optic cable, while CO2 lasers bounce it along a path of mirrors.
• Focus. A lens in the cutting head concentrates the beam, and the focal point is set relative to the sheet surface.
• Pierce. A pulsed beam burns a starting hole. On thick plate this takes noticeably longer, so the pierce point is placed in scrap with a short lead-in to the contour.
• Cut. The CNC moves the head along the contour while assist gas flows through the nozzle and pushes the melt out of the bottom of the kerf.
• Unload and finish. Small tabs that held parts in the sheet are broken, edges are deburred if needed, and parts move on to bending, welding or coating.

What goes wrong is usually visible on the bottom edge. If speed or gas pressure is off, molten metal sticks there as dross. Very small holes can show a bulge where the lead-in starts. And when many small parts are nested tightly in thin sheet, heat builds up in the remaining skeleton and can warp the last parts cut. Good programming, not more laser power, fixes most of these.

Assist Gas: Oxygen, Nitrogen or Air

The gas choice changes speed, cost and the edge you get, so it is worth understanding even if you never run a machine.

Gas	How it works	Typical use	Edge result
Oxygen	Reacts with hot steel and adds heat to the cut	Carbon steel, especially thicker plate	Fast, with a dark oxide layer on the edge
Nitrogen	Inert, simply blows the melt out	Stainless steel and aluminum	Bright, clean, oxide-free edge
Compressed air	Mostly nitrogen with some oxygen	Thin sheet where cost matters	Low cost, with slight edge oxidation

Our view: if a carbon steel part will be powder coated or welded, ask for nitrogen-cut edges or plan to remove the oxide. Coating applied over oxygen-cut scale can flake off at the edges later.

Three Ways the Beam Removes Material

• Fusion cutting (melt and blow) melts the material and uses inert nitrogen to blow it out. It is the main method for stainless steel and aluminum.
• Flame or reactive cutting uses oxygen, which burns with the hot steel and supplies extra energy. It cuts thick carbon steel faster at lower laser power.
• Vaporization cutting heats the material straight to vapor. It suits acrylic, wood, paper and thin films, usually with a CO2 laser.

Types of Laser Cutters: Fiber, CO2 and Nd:YAG

Laser type	Wavelength	Best for	Notes
Fiber	About 1.07 µm	Steel, stainless, aluminum, copper, brass	Energy efficient, handles reflective metals, fast on thin and medium sheet
CO2	10.6 µm	Acrylic, plastics, wood, rubber, foam, thin metals	Leaves a polished edge on acrylic; long wavelength reflects off bare aluminum and copper
Nd:YAG	1.064 µm	Fine precision work, thick or hard alloys, drilling	High peak power in pulses; less common for general sheet cutting today

Fiber lasers generate light inside a doped glass fiber, which gives a small spot and high efficiency. CO2 lasers excite a gas mixture, and their longer wavelength is absorbed well by organic materials. Nd:YAG lasers use a solid crystal and deliver short, powerful pulses.

Our view: for sheet metal parts, fiber is the default today. CO2 still earns its place on acrylic, wood and other non-metals, and Nd:YAG is a specialist tool. At Tuowei Precision we run all three types, with laser sources up to 10 kW, so the laser is matched to the material rather than the other way round.

What Materials Can Be Laser Cut?

Metals are the main industrial use. We regularly cut carbon steel, stainless steel (including 304 and 316), aluminum alloys such as 5052, 6061 and 7075, copper, brass and titanium. Non-metals include acrylic, engineering plastics, rubber, foam and wood.

Maximum thickness depends on the material and laser power. On our equipment:

Material	Maximum thickness
Carbon steel	Under 25 mm (0.98 in)
Stainless steel	Under 15 mm (0.59 in)
Aluminum	Under 15 mm (0.59 in)
Copper	Under 12.7 mm (0.5 in)

Materials You Should Not Laser Cut

Some materials should not be laser cut at all. PVC releases chlorine compounds that are toxic and corrode the machine. PTFE gives off fluorine compounds when heated. Polycarbonate tends to burn and discolor rather than cut cleanly. Fume extraction and beam enclosure matter for every laser, and OSHA lists the laser hazard standards that apply to these machines in general industry.

How Accurate Is Laser Cutting?

Laser cutting is accurate enough for most sheet metal work without secondary operations. These are the capabilities of our laser cutting process:

Specification	Value
General dimensions	ISO 2768-c, typically ±0.2 mm (0.008 in)
Repeatability	±0.05 mm (0.002 in)
Positioning accuracy	±0.10 mm (0.004 in)
Kerf	About 0.5 mm (0.02 in)
Minimum part size	2 × material thickness, minimum 1 mm (0.04 in)
Edge condition	Matte, with fine vertical lines
Lead time	5 to 7 days

ISO 2768-1 defines four general tolerance classes: fine (f), medium (m), coarse (c) and very coarse (v). Stating the class on your drawing tells the shop which tolerance applies to every dimension you have not toleranced individually.

Two Details That Trip People Up

Two details trip people up. First, the CAM software offsets the cutting path by half the kerf, so the part comes out at the drawn size. Do not add kerf to your drawing yourself. Second, on thick plate the cut edge has a slight taper and a wider heat-affected zone, so holes that need a precise fit are better drilled or reamed after cutting.

Accuracy also depends on the part, not just the machine. A long, thin part can move slightly as stresses in the sheet release, so very tight flatness or straightness may need extra steps.

What Is Laser Cutting Used For?

Laser cutting turns flat stock into profiles, so it shows up wherever sheet or plate parts are needed. Common uses include:

• Flat blanks for forming: brackets, chassis and enclosures that are cut first and then bent.
• Structural parts: frames, gussets, mounting plates and machine guards.
• Functional parts: shims, gaskets, washers, gears and spacers.
• Electronics: enclosure panels, front plates, insulation layers and circuit board panels.
• Decorative work: signage, architectural panels and engraved logos or part numbers.
• Prototypes: fast design iterations with no tooling to make.

The industries that use laser cutting most include automotive, aerospace, consumer electronics, medical devices, robotics and automation, industrial machinery and construction. In most of these, laser cutting is the first step of a wider sheet metal fabrication workflow that continues with bending, welding, hardware insertion and finishing.

How It Compares: Plasma, Waterjet and Punching

Process	Best at	Limits
Laser cutting	Thin to medium sheet, fine detail, narrow kerf	Thickness ceiling; reflective metals need fiber; small heat-affected zone
Plasma cutting	Thick conductive plate at high speed and low cost	Wider kerf, rougher and slightly beveled edge; conductive metals only
Waterjet cutting	Almost any material, very thick stock, no heat	Slower; abrasive adds running cost
Turret punching	High volumes of standard holes, louvers and forms	Needs a tool for each shape; less suited to complex contours

Our view: laser is the first choice for most sheet parts up to medium thickness because it combines accuracy, speed and no tooling. Switch to waterjet when heat would damage the material, and to plasma for thick structural plate where edge quality matters less than cost.

Design Tips and Common Mistakes

• Features too small for the thickness. Keep holes and slots at least as wide as the material is thick, and respect the minimum part size of twice the thickness.
• Kerf added to the drawing. Send true geometry. The shop compensates for kerf in the program.
• Messy files. Remove duplicate lines, close open contours and convert text to outlines before sending a DXF.
• Webs that are too narrow. Thin strips between cutouts overheat and distort. Keep them at least one material thickness wide.
• Holes too close to bend lines. They stretch when the part is formed. Add bend relief and check spacing with our metal bending guidelines.
• Gauge numbers without a thickness. Gauge means different things for steel and aluminum, so state thickness in mm or inches. Our sheet metal gauge chart shows the conversions.
• Coating over oxygen-cut edges. If a part will be powder coated, mention it so the edges are cut with nitrogen or cleaned first.
• One tight tolerance for the whole drawing. Apply a general class such as ISO 2768-m and call out tight tolerances only on features that need them.

Frequently Asked Questions

Can a Laser Cut Metal?

Yes. Metal is the most common material for industrial laser cutting. Fiber lasers cut carbon steel, stainless steel, aluminum, copper, brass and titanium. Maximum thickness depends on power and material; our machines cut carbon steel up to about 25 mm and stainless steel or aluminum up to about 15 mm.

What Are the Different Types of Laser Cutting?

The three main laser types are fiber, CO2 and Nd:YAG. Fiber lasers lead in metal cutting, CO2 lasers suit acrylic, wood and other non-metals, and Nd:YAG lasers handle specialist precision work. By technique, cutting is done by fusion with nitrogen, flame cutting with oxygen, or vaporization.

What Is a CNC Laser Cutter?

A CNC laser cutter is a laser cutting machine whose motion is controlled by computer numerical control. The controller reads a program generated from your CAD file and moves the cutting head along each contour, setting power, speed and gas. Nearly all industrial laser cutters are CNC machines.

What Software Is Used for Laser Cutting?

Parts are usually drawn in CAD software such as SolidWorks, Fusion or AutoCAD and exported as DXF or STEP files. CAM and nesting software then arranges parts on the sheet, assigns cutting parameters and generates the G-code that the laser machine runs.

What Is the Difference Between Laser Cutting and Plasma Cutting?

Laser cutting uses a focused light beam and gives finer detail, narrower kerf and cleaner edges on thin and medium sheet. Plasma cutting uses an ionized gas arc, works only on conductive metals and is faster and cheaper on thick plate, but leaves a rougher edge.

Getting Laser Cut Parts Made at Tuowei Precision

At Tuowei Precision we run fiber, CO2 and Nd:YAG laser cutters with sources up to 10 kW, and our quality system is certified to ISO 9001:2015, ISO 13485, IATF 16949:2016 and AS9100D. Typical laser cutting lead time is 5 to 7 days.

Upload a STEP, STP, SLDPRT, DXF, IPT, PRT or SAT file with the material, thickness, quantity and finish. Our engineers review every drawing before quoting and flag design issues before cutting. Parts that also need tapped holes or milled pockets move straight into our CNC shop, so they arrive ready to assemble. Start with our laser cutting services page.

About the Author

About the author: Leon Xu is an engineer at Tuowei Precision. He reviews customer drawings, gives DFM feedback and plans CNC machining processes to hold tight tolerances.