Laser Engraving Metal with xTool: Steel, Aluminium, Brass, Gold — Complete Guide

Metal laser engraving is one of the most commercially valuable laser applications — and one of the most misunderstood. The most common mistake is purchasing a diode laser expecting it to mark metal, only to find the 450nm wavelength reflects off bare metal surfaces without effect. Metal requires a specific approach depending on the type of metal, the desired result, and the production volume. This guide explains what is possible with each xTool machine and which is right for each application.

Why Metal Requires a Different Laser Wavelength

Metal surfaces reflect visible light — which is why they appear shiny. The 450–455nm blue wavelength used by diode lasers reflects off bare metal rather than being absorbed. The exception is coated or anodised metals: anodised aluminium has a surface layer that absorbs the diode wavelength, which is why diode lasers mark anodised aluminium but not bare aluminium.

Effective metal marking requires 1064nm — the infrared wavelength range where metals absorb rather than reflect. All fiber and IR lasers in the xTool range operate at 1064nm.

Four Types of Metal Laser Processing

Surface Marking (Oxidation)

The most common application. The laser heats the metal surface to create a controlled oxide layer — a permanent, flush, scratch-resistant colour change. No material is removed. On stainless steel this produces marks from straw-yellow through blue and purple depending on temperature. On tool steel it produces deep black annealing marks. Used for serial numbers, QR codes, surgical instruments, tool identification, and branded metal products.

Machines: All xTool fiber and IR machines. Speed and contrast increase significantly from the 2W IR (F1, F2) through 20W fiber (F1 Ultra) to 60W MOPA (F2 Ultra).

Colour Engraving on Stainless Steel (MOPA)

Standard fiber lasers produce oxidation in a limited colour range. MOPA lasers, with independent pulse width control, produce a full spectrum on stainless steel: vivid blue, gold, purple, red, and true black. Colours are permanent, produced by controlled oxide thicknesses, and require no pigments. Used for premium cutlery, trophy plaques, architectural hardware, branded surgical instruments, and luxury goods.

Machines: F1 Ultra (20W fiber — good colour range), F2 Ultra (60W MOPA — full spectrum, deepest saturation, most consistent results).

Deep Engraving (Material Removal)

At sufficient power, the fiber laser removes metal material creating a physically recessed mark. Used for industrial part marking that must survive abrasion, tooling marks, and high-wear environments where surface oxidation would be removed in service.

Machines: F1 Ultra (20W — light deep engraving on soft metals), F2 Ultra (60W MOPA — deep engraving on all metals including hardened steel).

Thin Metal Cutting

The F1 Ultra's 20W fiber cuts stainless steel up to 0.3mm, brass up to 0.4mm, aluminium up to 0.2mm. The F2 Ultra at 60W cuts up to 2mm on all three. Applications: metal stencils, jewellery blanks, decorative metal elements, and custom hardware previously requiring outsourced laser cutting.

Machine Comparison for Metal Applications

Application	F1 (2W IR)	F2 (5W IR)	F1 Ultra (20W fiber)	F2 Ultra (60W MOPA)
Stainless steel marking	Basic	Good	Fast, high contrast	Deep, full colour
Colour on steel	Limited	Limited	Good range	Full spectrum
Stainless steel cutting	✗	✗	Up to 0.3mm	Up to 2mm
Bare aluminium marking	Grey marks	Better marks	Black possible	True black, deep
Brass and copper	Basic	Good	Deep marks, colour	Full capability
Gold and silver (jewellery)	Basic	Good	Excellent precision	Best results
Titanium	Good	Good	Good colour range	Widest colour range
Anodised aluminium	✓	✓	✓	✓

Recommended Machines by Use Case

Jewellery and Precious Metals

Jewellery engraving requires precision above speed — fine detail on small objects, without heat damage to stones or settings. The F1 Ultra's 0.002mm accuracy and 10,000 mm/s galvo speed make it the correct machine for rings, pendants, bracelets, and watch cases. Deep, permanent marks on gold, silver, platinum, and titanium at commercial production speeds. The F2 Ultra MOPA adds colour capability for premium pieces.

Trophy and Award Manufacturing

Stainless steel and aluminium plaques in high volume. The F1 Ultra processes these at 10,000 mm/s — a batch of 20 plaques takes minutes not hours. The F2 Ultra MOPA adds colour options for premium trophy work.

Industrial Part Marking

Serial numbers, QR codes, data matrix codes, and compliance marks on metal components requiring permanence and scan-readability. The F2 Ultra MOPA's 60W power and MOPA pulse control produce marks to industrial traceability standards.

Market Traders and On-Site Personalisation

The F1 Portable's 2W IR + 2kg weight + USB-C power makes it the only professional metal-capable laser that operates on battery at a market stall. For traders doing on-site metal personalisation — keyrings, tags, cutlery — this combination is unique in the market.

Available from Eolas Prints

Eolas Prints is an authorised xTool reseller based in Cantabria, Spain. The full F-series range — F1, F1 Ultra, F2, F2 Ultra — ships to customers across Europe with EU warranty.