Material selection for laser cutting

Start with the job, not the metal

Four questions usually settle the choice:

• Will it corrode? Outdoors, wet, food-contact or marine pushes you toward stainless or, with a coating, mild steel.
• How much does weight matter? Aluminium is roughly a third the weight of steel for the same volume.
• Does it need to look a certain way? Brushed stainless, decorative brass and powder-coated steel each have a distinct finish.
• What's the budget and quantity? Mild steel is the most economical by a distance; brass and thick stainless are the priciest to buy and to cut.

Mild steel — the everyday workhorse

If a part doesn't need to be stainless or light, it's probably mild steel. It cuts fast and clean on a fibre laser, takes folding and welding well, and is by far the cheapest option. The trade-off is that bare steel rusts, so most parts are powder-coated, painted or zinc-plated afterwards — something we do in-house.

• Grades we cut: CR4 cold-rolled (smooth, clean surface, good for visible/coated parts) and S275 hot-rolled (structural, for brackets, base plates and gussets).
• Best for: brackets, frames, base plates, gussets, enclosures, general fabrication.
• Detail vs thickness: holds fine detail well up to ~6 mm; cuts cleanly all the way to our 20 mm maximum, with features sized to the thickness.

Stainless steel — corrosion resistance and a clean look

Stainless resists corrosion without any coating and keeps a bright, hygienic surface, which is why it dominates food, marine, architectural and medical work. It's denser and tougher than mild steel, so it's slower and dearer to cut, and cut edges can show a slightly different tone where nitrogen assist gas isn't used.

• 304: the general-purpose grade — indoor and most outdoor use, kitchens, splashbacks, trim.
• 316: adds molybdenum for better resistance to salt and chemicals — marine, coastal and harsh environments.
• Finishes: 2B (smooth mill finish) or brushed/grain. We can grain a surface and keep a protective film on visible faces to avoid scratches.
• Best for: fascia panels, food and hygiene equipment, marine fittings, architectural detail.

Aluminium — light, conductive, corrosion-resistant

Aluminium is the go-to when weight matters or you want natural corrosion resistance without the cost of stainless. It's about a third the density of steel and conducts heat and electricity well — hence enclosures, heatsinks and panels. It is more reflective, so very thick aluminium is harder to cut; within our range it cuts cleanly.

• 1050: nearly pure, soft, excellent corrosion resistance and formability — trim, panels, conductive parts.
• 5251 / 5083: stronger magnesium-alloyed grades that fold and weld well — structural panels, enclosures, marine.
• Finish: mill finish as standard; can be anodised (out-sourced) for colour and a harder surface. Note that powder coat keys to aluminium beautifully.
• Best for: enclosures, heatsinks, lightweight brackets, panels, signage.

Brass — decorative and electrical

Brass is chosen for how it looks — that warm gold tone for signage, nameplates and architectural detail — and for its electrical properties. It's the priciest of the four and, being reflective, is limited to thinner sections, but the laser holds crisp internal detail in it that's ideal for lettering and logos.

• CZ108: the common cold-working brass we stock.
• Best for: signage, nameplates, decorative panels, electrical contacts and busbars.

Thickness vs detail — the trade-off in one place

Across every material, finer detail lives in thinner stock. As plate gets thicker the smallest hole, slot and text stroke all grow — there's a full breakdown in the design guide. The table below is the quick comparison.

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