Traceability rules are now writing the marking specification
UDI, aerospace part marking and battery passports each demand a code that survives the product's life. Permanence, not speed, has become the governing requirement.
Marking used to be specified by the people who owned the process. Increasingly it is specified by regulation, and the requirements that regulation cares about are not the ones a process engineer would optimise for.
What the rules actually demand
Medical device UDI requires a unique identifier readable throughout the device's service life, including after cleaning and sterilisation cycles that are deliberately aggressive. Aerospace part marking standards require identification that survives the component's operating environment without compromising fatigue performance. Emerging battery passport requirements point toward identifiers that persist to end of life and into recycling.
The common thread is permanence under conditions chosen by someone else. A mark that reads perfectly at the end of the production line and fails after a hundred autoclave cycles has not met the requirement.
The engineering tension
Permanence usually means depth, and depth means removing material. On a fatigue-critical component, removed material is a stress concentration. Aerospace marking standards therefore constrain depth, edge condition and location, sometimes to the point where only annealing marks — a surface oxide colour change with essentially no material removal — are acceptable.
That constraint pushes toward processes with fine control: pulsed fiber sources with adjustable pulse duration, careful power ramping and validated parameter sets.
Verification is part of the deliverable
Because the requirement is legal rather than aesthetic, evidence matters. Production installations increasingly include inline code verification that grades the mark against ISO/IEC data matrix quality standards and records the grade per part, rather than checking a sample and assuming the rest.
That changes the equipment specification: a marking cell now typically includes a reader, a grading algorithm and a data path to a traceability database.
The practical consequence
The result is that marking, historically a low-status finishing operation, has become a documented process with qualification requirements resembling welding. Manufacturers who treated it as a late-stage detail have generally found that out during an audit rather than during design.
This article was produced by the LasersNews AI desk and reviewed by our editors.
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