A technical comparison of the three main metal cutting methods — and why we chose fibre laser for your signs.
For custom metal signs, CNC fibre laser cutting outperforms plasma and waterjet in precision, edge quality, and speed on thin sheet metal. Plasma cutting is better suited to thick industrial plate, while waterjet excels on heat-sensitive or extremely thick materials — neither of which apply to most signage.
A high-powered fibre laser beam — typically 1,000 to 6,000 watts — is directed through a series of lenses and mirrors to melt, burn, or vaporise the metal along a programmed path. The beam is incredibly narrow, producing cuts with minimal material loss. An assist gas (usually nitrogen or oxygen) blows molten material out of the kerf, leaving a clean edge. Fibre lasers are particularly efficient on reflective metals like aluminium and copper because the wavelength (around 1,070 nm) is absorbed well by these materials.
Plasma cutting forces an accelerated jet of hot plasma — electrically conductive ionised gas — through a constricted nozzle. The plasma arc reaches temperatures of 20,000°C or more, melting the metal and blowing it away. It is a powerful, fast process designed primarily for thick carbon steel plate in industrial fabrication. While modern CNC plasma tables can achieve reasonable accuracy, the inherent width of the plasma arc and the heat-affected zone limit fine detail.
Waterjet cutting uses a high-pressure stream of water — typically 60,000 psi or higher — mixed with abrasive garnet particles to erode the material. Because there is no heat involved, waterjet is ideal for materials that would warp, harden, or change properties under thermal cutting. It can cut virtually any material, including metal, stone, glass, and composites. The trade-off is speed: waterjet is significantly slower than laser or plasma on thin metal.
Precision matters enormously in sign-making. A business name with uneven letter spacing or jagged edges looks unprofessional. A wedding sign with wobbly script ruins the aesthetic.
Fibre laser achieves positional accuracy of ±0.05 mm and kerf widths as narrow as 0.1 mm. This means intricate serif fonts, delicate filigree, and tight internal cutouts are all possible. The edge is smooth, square, and consistent — often requiring no post-processing at all.
Plasma achieves positional accuracy of around ±0.5 mm to ±1.5 mm depending on the machine and material thickness. The kerf is wide — 1.5 to 3 mm — and the edge shows characteristic striations (drag lines) from the plasma arc. These must be ground off for a professional finish, adding labour cost.
Waterjet achieves accuracy of ±0.1 mm to ±0.2 mm with a kerf of 0.8 to 1.2 mm. The edge is smooth and matte, with no heat damage. However, the cut has a slight taper — the exit side is marginally wider than the entry side — which can be visible on very thin material if not managed.
All three methods can cut the materials we use at Metal Marvel — mild steel, stainless steel, and aluminium — but the results differ.
Mild steel: Laser cuts beautifully with oxygen assist, leaving a clean edge. Plasma cuts fast but leaves a wide kerf and heat discolouration. Waterjet cuts cleanly but slowly.
Stainless steel: Laser with nitrogen assist produces a bright, oxide-free edge. Plasma discolours the edge and compromises corrosion resistance locally. Waterjet works well but is slow.
Aluminium:Fibre laser handles aluminium exceptionally well because the beam wavelength is efficiently absorbed. Plasma struggles with aluminium's reflectivity and thermal conductivity. Waterjet works but abrasive consumption is high.
On 2 mm sheet metal — the standard thickness for our signs — fibre laser is both faster and cheaper than plasma or waterjet. A single 1200 × 2400 mm sheet can be fully processed in under 10 minutes on a modern fibre laser. The same sheet would take 30–60 minutes on waterjet and require significant post-processing if cut by plasma.
Operating costs also favour laser for thin material. Fibre lasers have high electrical efficiency (30–40%), minimal consumable costs, and near-zero maintenance between cutting sessions. Plasma consumes electrodes and nozzles rapidly. Waterjet consumes abrasive garnet continuously — up to 0.5 kg per minute — which adds significant material cost.
| Factor | Fibre Laser | Plasma | Waterjet |
|---|---|---|---|
| Precision | ±0.05 mm | ±0.5–1.5 mm | ±0.1–0.2 mm |
| Kerf width | 0.1–0.3 mm | 1.5–3 mm | 0.8–1.2 mm |
| Edge quality | Smooth, square, ready to finish | Striated, requires grinding | Smooth matte, slight taper |
| Heat-affected zone | Minimal | Large | None |
| Speed on 2 mm steel | Very fast | Moderate | Slow |
| Max thickness | ~25 mm (steel) | ~50 mm | ~150 mm |
| Aluminium | Excellent | Poor | Good (slow) |
| Post-processing | Minimal to none | Grinding required | Minimal |
| Running cost | Low | Moderate | High (abrasive) |
We chose CNC fibre laser cutting because it is the only method that delivers the precision, consistency, and finish quality our customers expect. Every sign we produce is cut on a state-of-the-art fibre laser machine optimised for thin sheet metal.
Each cutting technology has its place. Here is where each method shines — and where it falls short.
Choose fibre laser when: You need detailed text, fine features, or a premium finish on thin to medium sheet metal. This covers 95% of sign-making applications, from house numbers to wedding welcomes to business signage.
Choose plasma when: You are cutting thick steel plate (over 12 mm) for structural or industrial applications where edge finish is secondary to speed and cost. Plasma is not suitable for detailed signage.
Choose waterjet when: You are cutting heat-sensitive materials, very thick metal, or non-metal substrates like stone or glass. For thin metal signs, waterjet is overkill — slower and more expensive without meaningful benefit.
Experience the difference that CNC fibre laser cutting makes. Every sign we produce is cut with millimetre accuracy and finished to the highest standard.
By the Metal Marvel Team
Last updated: May 2026