Using fine silver wire for your jewellery or sculpture creations is appealing because of its malleability. However, once you have bent and worked the wire into its desired shape, you must harden it for it to retain that shape. Hardening causes the large crystals in the soft wire to break down into smaller crystals, which make it firm and stiff.
As you work with the wire, the bending and shaping actually begins the hardening process. Some craftspeople will bend a wire into various shapes before beginning the final creation for this reason. However, if wire is shaped too much, it can harden too quickly and become brittle and break. If handling the wire doesn't harden it enough, tapping lightly on it with a rawhide or rubber mallet (that won't scar the wire) also hardens it.
Tumbling the wire piece after it has been shaped into its final form is another means of hardening it. Either a rotating or vibrating tumbler, filled with enough stainless steel shot (small, irregular shaped pieces of stainless steel), water and burnishing agent (such as dish-washing detergent) to cover the piece is sufficient. Tumbling burnishes the piece with gentle contact by the shot on all surfaces of the wire, urging the large crystals to break down slowly.
Anneal and Quench
Best performed in a well-equipped workshop under the guidance of an experienced professional, this process involves heating the fine silver wire to its annealing temperature (customarily 649 degrees Celsius), quenching it in water, then allowing it to completely cool on a heat-protected workbench. The quick heating and cooling causes the large crystals to break down quickly and harden completely.