They can be found in every household and factory canteen, and they always seem to be from a single cast. However, sinks out of stainless steel actually have welding seams. That you do not see them often enough has to do with Laserline's diode lasers: they make technically and economically optimal heat conduction welding possible, which leaves no visible marks.
When thermal expansions of pipelines must be compensated or vibrations between vacuum pumps and measuring instruments must be decoupled, metal bellows are used. Welding thin and flexible membrane pairs requires an even heat input that creates stable, crack-free welding seams. Here, Laserline's diode lasers provide excellent results.