Brazing of frames, bridges and rims: welding is generally by induction and less commonly by torch. These small joints are brazed in a short time (3/5 seconds) and often repeatedly with a controlled temperature below 560°C. The choice of filler material is limited to alloys with high silver content, low melting and high fluidity and wettability, mostly in normalised wire with very thin diameters (<<0.5 mm), in skeins or reel-coiled.

The alloys used and the difficulty of final cleaning constrain the choice to a powder flux with extra-fine grain size or a paste with specific homogeneity and consistency.