By law, each gold bar, no matter the size or shape, must be mandatorily marked and serialized before being placed on the market. This is done for security, coding and traceability reasons. According to the rules imposed by London Bullion Market – the London market for gold and silver (LBMA) each ingot must have certain specific information-tied markings, such as:
Industrial marking, or commonly called stamping operation, is not easy. The marking techniques imperially cannot alter or modify the shape, size and above all, weight of the ingot. Hence, the only marking technologies allowed are those which fully respect these characteristics.
How do you mark a gold ingot?
Among the various marking technologies, the most suitable are the following:
1) Impact Marking
2) Dot Peen Marking
3) Scribe Marking
4) Laser Marking
Is the least expensive and, at the same time, a fast and deep marking solution. With both manual or pneumatic operation, it is normally used with numbering heads for serialization of the ingot (as shown in the example photos).
Dot peen marking
This technology allows to mark ingots with maximum flexibility because of its software-driven and progressive electronic nature. Thanks to its’ pneumatic and electric characteristic, the dot peen machine is useful and adaptable to different types of markings: deep, continuous or “light/superficial”.
Scribe marking consists of a tip that “scratches” on the surface of the material being marked, thus producing a continuous line. This technology can only be used on ingots with perfectly flat surfaces.
This is the least used solution, but, thanks to new technologies and new types of lasers, it is considered a valid solution on some processes. Laser machines are software-driven and thus guarantee maximum flexibility in the marking process. However, it is important to know that marking with lasers can be problematic with ingots due to the consequential evaporative-stress the material undergoes during its’ marking. This can cause possible weight loss of the ingot.
Not just gold
Marking and coding rules are not only valid for gold bars, but also for silver, palladium, and/or platinum. These materials must be marked too with the technologies described above.
So how can I choose?
As in all industrial applications, the right strategy is to rely on experienced professionals with a solid knowledge base, application expertise and history.
Automator designs, manufactures and sells industrial marking equipment worldwide. We have been doing this since 1940. We are the only international company that provide all marking technologies for all industrial processes. Automator, through its worldwide team, also provides advisory services to companies seeking the best technology for each type of process and for each type of investment, relying on Automator’s wide range of machines and systems.