Welder ID Stamp
The welder's stamp is a hardened striking tool with a personal identification number. The welder strikes this number permanently into the component next to the weld. This way, each weld can be clearly traced back to a welder and their qualification.
Physico-Chemical Mechanism of Action
A hardened steel stamp has raised lettering or numbers. The welder places the stamp on the part surface and hits it with a hammer. The blow plastically deforms the metal. The raised impression is pressed into the material as a permanent indentation. The mark stays legible even after welding and under normal service. The stamp works purely mechanically – no chemical reactions take place.
Metallurgical Relevance & Risks in Welding
Every stamped mark creates a sharp edge. That edge acts like a notch. Under tensile or fatigue loading, a crack can start at this notch. This is especially critical with high-strength steels, cold-formed parts, or components under dynamic loads. Stamping directly in the weld is also forbidden. The weld already has a coarse cast structure and is sensitive to extra notches. On stainless steels, the blow destroys the protective chromium oxide layer. This increases corrosion susceptibility at the stamp location.
Workshop Practice & Action Instructions
Place the stamp only on the base material. Keep at least 10 mm away from the weld toe. Use a solid backing or counter-support so the blow is clean and one-shot. Use only fully legible and tested welder stamps. Do not strike on strongly curved surfaces or areas under high existing stress. After stamping, check the legibility of the mark. For high-strength steels or dynamically loaded parts, check whether stamp marking is permitted. If not, use alternative marking such as paint pen, sticker, or a few blows only in a non-critical area.