MALLEABILITY

Malleability refers to the property of a solid, particularly a metal, to undergo permanent deformation under compressive stress or impact — hammering, rolling, stamping, striking — without breaking or cracking. It allows the material to be flattened, drawn into thin sheets, or shaped, and is distinct from ductility, which concerns the elongation of a material under tensile stress, for example during wire drawing. In watchmaking, this quality is essential for working precious metals and alloys: gold, the most malleable of all metals, can be beaten into sheets a few tenths of a micron thick; silver, Copper, brasses brasses and Main plate — despite its high density, which explains its use for high-end cases and components — are also among the most malleable metals. This property allows for repoussé work, planishing of cases, or the making of dials. Malleability varies with temperature and the structural state of the metal: annealing, by relieving internal stresses accumulated during Cold working caused by cold work, restores the flexibility of a hardened part and facilitates subsequent shaping operations.