Laser, waterjet or plasma: how to choose the cutting method
At our plant at ul. Elektronowa 6 in Lodz, we cut sheet metal using three methods: laser, waterjet and plasma. Here is how we match the method to the part and what to include in your enquiry.
We usually choose a sheet metal cutting method based on three factors: what the part is made of, its thickness, and what will happen to its edge next. We have a dedicated machine for each method, so the choice comes down to which one will cut the part best.
Sheet metal cutting methods: when to use laser, plasma or waterjet
- Laser, when a smooth edge, small holes and intricate contours matter in steel, stainless steel and aluminium sheet metal.
- Plasma, when cutting thicker structural steel and the edge does not need laser-like quality—for instance, when the part will be welded or machined anyway.
- Waterjet, when the material must not heat up or is non-metallic: plastics and stone, such as granite.
Many parts can be cut using two methods. The choice then depends on the edge and the subsequent operations on the part. We write more about sheet metal laser cutting in our post 12 kW fibre laser at ECAD.
Which machines stand behind each method
The machine determines what can be cut. The table lists our three cutting machines, materials, and maximum thicknesses for laser and plasma.
| Method | Machine | Material and thickness | When we choose it |
|---|---|---|---|
| Laser | HSG G3015H V2, 12 kW, sheets 3000 × 1500 mm | structural steel, stainless steel and aluminium up to 40 mm, brass up to 16 mm, copper up to 12 mm; structural steel up to 20 mm with a high-quality edge | smooth edge, small holes and intricate patterns |
| Plasma | STIGAL with Hypertherm HPR130XD plasma source, 130 A, working area 3000 × 1500 mm | structural steel: piercing up to 32 mm, cutting max. up to 38 mm; stainless steel and aluminium: piercing up to 20 mm, cutting max. up to 25 mm | thicker structural steel, when the edge will undergo welding or machining |
| Waterjet | PTV waterjet cutting machine | metals (mainly steel, also aluminium), plastics and stone (e.g. granite) | heat-sensitive materials, plastics, stone |
The thicknesses for laser and plasma are the maximum values for the machines. We confirm the thickness and edge quality for a specific order—and for waterjet, also the material type—when preparing the quote.
Heat, edge quality and accuracy
Laser and plasma cut with heat, creating a heat-affected zone along the edge. A waterjet cuts cold, so there is no such zone. This is important for materials that must not be heated.
Plasma cutting vs laser cutting
A laser-cut edge is usually smoother than a plasma-cut one, and small holes come out better on the laser. Our laser cuts structural steel with a high-quality edge up to 20 mm. With plasma, we pierce structural steel up to 32 mm and cut it up to a maximum of 38 mm. Above 20 mm, both our laser and plasma cut structural steel, so the deciding factors are the edge and what happens to the part next: if it goes to welding or a machine tool, plasma is often sufficient.
Waterjet cutting vs laser cutting
Both laser and waterjet cut metal sheets; on the waterjet machine we mainly cut steel. The laser is usually faster on thin sheet metal and better for fine patterns. We choose waterjet when the material should not heat up at the cut or when it is not metal: we cut metals on the laser, and plastics and stone with the waterjet.
If any dimension has a tight tolerance, mark it on the drawing. We will select the method accordingly.
Example: flange from a 20 mm plate
On some production drawings from our archive, the designer enters the cutting method in the “Process” field. For this flange, the note reads: 1) waterjet cutting, 2) reaming of dia. 8.1 hole. Thus, the drawing specifies hole sizing after cutting.
After cutting: deburring, bending and welding in a single order
Cut parts do not need to be sent to another company. Within the same order, we deburr them, bend them on a press brake (Trumpf TruBend 7050), weld them in our welding shop, or machine them on CNC machines. What can be done with a given part depends on the material and thickness; we verify this when preparing the quote.
We accept orders from a single piece. We do not give fixed prices upfront: we quote from a drawing or model, and the price depends on the material, thickness, cutting length, quantity and post-cutting operations. Details are available on the cutting and bending price list page.
What to include in your enquiry
To help us select the right method, please state in your message:
- the material and grade of the part,
- the thickness and how many pieces you need,
- what will happen to the edge after cutting: welding, bending, machining, or assembly without further processing,
- which dimensions have tight tolerances.
We prepare laser cutting programmes in SigmaNEST, and a DXF file with the contour and holes is the most convenient format for cutting.
