Case study

How can you guarantee permanent serial number marking on raw-material bars stored outdoors?

Permanent raw-material marking ahead of machining

Our customer is a manufacturer specializing in industrial boilermaking and fabrication and the machining of high-performance alloys, mainly for the aerospace and nuclear sectors. Its operations require materials like steel, stainless steel and Inconel, which arrive as large unmachined bars and are kept in an outdoor storage area until machining. Every bar needs to be identifiable at any point in time (serial number, material reference, lot number) in order to ensure the traceability that companies in this sector require.

Marking stainless steel bars stored outdoors: the shortcomings of markers and tags

At first, the unmachined bars were identified with a felt marker or with tags fastened to the end of the bar. Outdoors, the ink washes out and the tags break down. Concretely, some bars were found with no visible identification at all, and the precise material could no longer be read off the bar, a situation that cannot be tolerated when working with aerospace alloys, where material traceability is what underpins compliance.

Several constraints had to be taken into account when selecting a solution:

• • The parts are long and heavy: moving an unmachined bar to a fixed marking station is not an option; the machine must travel to the bar, outdoors included
  • The marked materials (stainless steel, Inconel) are hard and require a technology that can engrave a durable marking into the metal
  • Volumes consist of small and medium production runs: building this marking step into an automated line would not be cost-effective. Large runs of smaller parts are already laser marked in-house

The need boiled down to permanent marking of large-size bars, done right on site outdoors, with no part handling and no dedicated infrastructure.

Dot peen marking: a permanent marking solution for raw-material bars

The customer’s chosen solution is the e-MARK EVO, a portable dot peen marking machine supplied as a standard model. Dot peen marking produces a mechanical deformation in the material, meaning the mark is engraved into the bar instead of sitting on its surface. On both stainless steel and Inconel, the marking stays readable over the long run, even after lengthy exposure to outdoor weather.

The portable design of the e-MARK EVO solves the main logistical issue: the operator brings the machine to the bar, whether it is sitting in the outdoor storage area or in the plant. A part several metres long no longer needs to be transported to a fixed marking station. A single machine handles all marking requirements for large parts, in addition to the laser already used for high-volume runs of small parts.

Since the equipment is a standard product in the SIC MARKING catalogue, it required no specific development: the solution was commissioned quickly, at a cost that matches its use on small and medium production runs.

Permanent marking of bars: long-term material traceability outdoors

The unmachined bars now feature permanent marking applied on the spot, wherever they are stored or used. Material identification no longer relies on a marker or a tag standing up to the weather over time. Pairing dot peen marking with the portability of the e-MARK EVO fits the usage profile precisely (limited runs, long parts, hard materials, outdoor setting) without over-investing.