Laser welding focuses a concentrated beam of light onto a seam, melting the metal in a very small spot to fuse two parts. Because the energy is so concentrated, the surrounding area heats up far less than with other methods — this is called a small heat-affected zone.

For thin steel, that control matters. Thin stainless deforms and oxidizes easily when overheated, and a wide heat-affected zone can weaken the material right where the weld should be strongest. Laser welding is cleaner and more precise than TIG for these parts.

In drinkware, laser welding is used on vacuum-critical seams — the joins around the inner and outer walls, and often the tail-plug closure after evacuation. A clean, narrow weld here means less discoloration and a better-looking, stronger seam.

Practical takeaway: When comparing suppliers, look at the weld seams on production samples for width and discoloration, which reflect the control of the laser welding process.