STAMPING

Stamping consists in creating an imprint — pattern, inscription or relief — by pressing under high pressure a Die engraved into the surface of a metal piece. The operation is performed using a press, mechanical eccentric or hydraulic, which abruptly applies a punch onto the blank to be decorated, placed between the die and counter-die. Depending on the engraving of the tooling, the pattern appears recessed, in relief, or combines both in a single strike. In watchmaking, this is used in particular to stamp Index (hour marker) and Applied marker on certain dials, logos, case backs of certain Case and certain decorative movement elements; the same technique is at the origin of coin striking and medal striking. Stamping deforms the material cold through Cold working, which requires a Metal sufficiently malleable — Brass, Gold, Silver — and, depending on the depth of relief sought, an intermediate annealing to restore the Ductility lost during Cold working and avoid cracking. The precision of the result depends on the quality and wear of the Die, the force and speed of application, as well as the rigorous centering of the blank under the tooling.