Laser cutting is usually the fastest and most accurate choice for thin and medium sheet metal. Plasma cutting is usually the cheapest way to cut thick carbon steel when edge finish is not critical. Waterjet cutting is slower and dearer per metre, but cuts almost any material at almost any thickness, with no heat at the edge. The right choice comes from the material, the thickness, the accuracy you need and what happens to the edge next.
Key points
- Laser: fastest and most precise in thin to medium sheet; small heat-affected zone; narrow kerf.
- Plasma: conductive metals only; cheapest per metre in thick steel; wider kerf, bevel and dross.
- Waterjet: almost any material and thickness; no heat; slowest and usually dearest per metre.
- Cost per part is cut length times cost per metre, plus pierces, material and any edge clean-up.
- Choose by material and thickness first, then by tolerance and edge, then by cost.
How each process cuts
Laser. A focused beam melts or vaporises the material along the cut line, and an assist gas (oxygen, nitrogen or air) blows the molten material out of the kerf. Fibre lasers dominate sheet metal work today. Laser cutting is fast and accurate in thin material and slows down steeply as thickness grows.
Plasma. An electric arc through a gas forms a jet of plasma hot enough to melt metal, and the gas blows it away. Because the workpiece is part of the electrical circuit, plasma cutting only works on conductive metals. It cuts thick steel quickly with relatively cheap equipment. High-definition plasma systems narrow the gap with lasers on accuracy and edge quality.
Waterjet. Water at very high pressure, usually with abrasive garnet mixed in, erodes the material along the cut. Waterjet cutting puts no heat into the part and works on almost anything: metals, stone, glass, ceramics, composites, rubber and foam. Pure-water jets, without abrasive, cut soft materials such as foam, gaskets and food.
Side-by-side comparison
The ranges below are typical, not limits. They vary with the machine’s power, the material and the edge quality you accept, so check them against the machines you actually run.
| Laser (fibre) | Plasma | Waterjet (abrasive) | |
|---|---|---|---|
| Materials | Metals; some plastics, wood and other non-metals on suitable lasers | Electrically conductive metals only | Almost anything: metals, stone, glass, composites, plastics, rubber |
| Sweet spot | Thin to medium sheet | Medium to thick carbon steel | Thick sections, heat-sensitive or non-metallic materials |
| Maximum thickness | Rises with laser power; high-power machines cut thick plate, but most work is thinner | Thick plate, well beyond typical laser work | The thickest of the three, slowly |
| Accuracy | Best of the three, especially in thin sheet | Lowest; high-definition plasma is much better than conventional | Good; taper needs compensating in thick material |
| Kerf | Narrowest, a fraction of a millimetre | Widest, a few millimetres in thick plate | Around a millimetre, set by the nozzle |
| Heat-affected zone | Small | Larger; can harden the edge of some steels | None |
| Edge | Clean, near square; oxide layer if cut with oxygen | Slight bevel, possible dross; often ground before welding or painting | Smooth matt finish; slight taper |
| Speed | Very fast in thin sheet, slows steeply with thickness | Fast in thick steel | Slowest |
| Running cost | Electricity, assist gas, lenses and nozzles | Electrodes, nozzles and gas | Abrasive, pump wear and high-pressure parts |
| Typical cost per metre | Lowest in thin sheet | Lowest in thick steel | Highest in most metals |
What each costs to run
The cost of a cut part follows the same structure for all three: cut length divided by cutting speed gives time, time multiplied by the machine’s hourly rate gives the machine cost, and each pierce adds a fixed time. Our guide to laser cutting cost works through that method step by step. What differs is the hourly rate, the speed at each thickness and what the edge needs afterwards.
Waterjet’s hourly rate includes abrasive, which is consumed continuously and is often one of its largest running costs, plus wear on the high-pressure pump and nozzle. Plasma consumables (electrodes and nozzles) wear with each pierce and arc-hour. A fibre laser’s running cost is mostly electricity and assist gas, with nitrogen cutting of thick stainless steel consuming a lot of gas.
Worked example: 4 metres of cut in 10 mm steel
The rates and speeds below are illustrative assumptions chosen to show the method, not measured cutting speeds or market rates. Your own machines will give different numbers. The job is a mild steel part with 4 m of cut length in 10 mm plate; the part will be painted, so the plasma edge needs grinding.
Worked example: machine cost for the same part (illustrative rates and speeds)
| Line | Laser | Plasma | Waterjet |
|---|---|---|---|
| Hourly rate | €150/h = €2.50/min | €90/h = €1.50/min | €120/h including abrasive = €2.00/min |
| Illustrative speed in 10 mm steel | 1.25 m/min | 2.0 m/min | 0.25 m/min |
| Cost per metre | €2.50 ÷ 1.25 = €2.00/m | €1.50 ÷ 2.0 = €0.75/m | €2.00 ÷ 0.25 = €8.00/m |
| Cutting 4 m | 4 × €2.00 = €8.00 | 4 × €0.75 = €3.00 | 4 × €8.00 = €32.00 |
| Edge clean-up | none | 5 min × €42/h = €3.50 | none |
| Total per part | €8.00 | €6.50 | €32.00 |
In this example plasma is cheapest, even after grinding, and waterjet costs four times the laser. Change the assumptions and the order changes. In 3 mm sheet the laser would be several times faster and would almost certainly win. In 50 mm plate the laser might not cut at all, leaving plasma for speed and waterjet for accuracy. And if the part were hardened tool steel, or glass, or the edge had to be free of heat effects, waterjet would be the only choice regardless of price.
Material and nesting matter for all three: the part pays for the sheet it uses, not just its own area. The kerf differs between processes, so the gap between nested parts does too; our article on nesting and material utilisation covers how that is charged.
How to choose
| If the job is | Usually choose | Why |
|---|---|---|
| Thin or medium sheet steel, stainless or aluminium | Laser | Fastest, most accurate, clean edge |
| Many small holes or fine detail in sheet | Laser | Narrow kerf, small minimum features |
| Thick carbon steel, structural parts, edge to be welded | Plasma | Fast and cheap in thick plate |
| Very thick metal plate | Waterjet or plasma | Beyond most lasers |
| Heat-treated or heat-sensitive parts | Waterjet | No heat-affected zone |
| Stone, glass, ceramics, composites, rubber, foam | Waterjet | The only one of the three that cuts them |
| Tight tolerances on thick parts | Waterjet with taper compensation, or cut and machine | Plasma bevel and laser striation limit accuracy |
Two questions settle most cases. Does the material conduct electricity, and how thick is it? That rules options in or out. Then: what tolerance does the part need, and what happens to the edge next? A weld prep tolerates a plasma edge; a visible, painted cosmetic edge may not; a mating face may need machining whatever cut it. Our guide on how tolerances drive machining cost explains why tight values cost more on any process.
After the cut
Most cut parts go on to other operations: bending, inserts, welding, finishing. A plasma-cut part may need grinding before any of those; a laser-cut part usually goes straight to the press brake. The sheet metal fabrication cost guide covers the whole route.
Quotometry prices all three today from a DXF or SVG drawing, on one shared cutting model with a material and thickness table per technology; engraving is offered on the laser only (see waterjet and plasma cutting).
Questions people ask
Which is cheaper, laser, plasma or waterjet cutting?
It depends on the material and thickness. In thin sheet metal a laser is usually cheapest because it cuts fastest. In thick carbon steel, plasma is often cheapest per metre, though its edge may need grinding. Waterjet is usually the slowest and most expensive per metre but cuts materials and thicknesses the others cannot, without heat.
Can plasma cut stainless steel and aluminium?
Yes, plasma cuts any electrically conductive metal, including stainless steel, aluminium and copper alloys. It cannot cut non-conductive materials such as plastics, glass, stone or wood. The edge on stainless and aluminium is usually rougher than on carbon steel, so parts that need a clean edge are often laser or waterjet cut instead.
Why choose waterjet if it is slower?
Because it cuts almost anything (metals, stone, glass, composites, rubber, foam) and adds no heat, so there is no hardened or discoloured edge and no heat distortion. That matters for heat-treated or tempered parts, for materials that melt or burn, and for very thick sections that a laser cannot cut at all.
What edge quality does each process give?
A laser gives a narrow, clean, nearly square edge in thin sheet, with some striation in thick plate. Waterjet gives a smooth, matt edge with a slight taper unless the machine compensates. Plasma gives a wider kerf, a slightly bevelled edge and often some dross, which may need grinding before welding or painting.
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