Annealing marking or laser annealing: definition and principle

Annealing marking (also known as laser annealing) is a laser marking technique primarily used on stainless steel materials.
Unlike other processes (engraving, ablation), no material is removed: the marking is created by modifying the surface structure of the metal.
The laser locally heats the material surface to a temperature typically between 200 and 500 °C, triggering a controlled oxidation process. This reaction produces a thin colored oxide layer—usually black, brown, or bluish—without etching or penetrating the surface.

Technical characteristics

• Non-destructive process: the surface remains perfectly smooth.
• High resistance: the marking withstands cleaning, chemicals, and corrosion.
• High precision: enables very fine markings, suitable for Data Matrix codes, QR Codes, or logos.
• Marking speed: slower than other laser processes (as it relies on gradual heating of the metal).
• Compatible materials: mainly stainless steels, and in some cases titanium or special alloys.

Typical applications

Annealing marking is particularly used in industries where:

• Surface integrity must be preserved;
• The marking must remain readable and durable over time;
• Hygiene or safety standards require perfectly smooth surfaces (e.g. medical, food processing, pharmaceutical industries).

Application examples:

• Medical instruments
• Stainless steel components for the food processing industry

Design or decorative stainless steel components