A secondary fastening used for securing jewellery that guarantees the safety of the jewellery should the main fastening break. Usually seen as a hinged loop that snap closes one side of a clasp to the other.
A safety catch is a safety system used in case the main clasp opens. It is usually a hinged loop that is attached to one side of the clasp and will snap closed onto the other side.
Added to a closure to prevent the opening of a clasp.
One of several means of securing a brooch to a garment. Before the invention of safety catches, the most common means of securing a brooch was a simple "C" catch with no locking mechanism. A safety catch is simply a way to secure the pin to the "C" catch so that it doesn't come undone and does not need to extend beyond the edge of the brooch.
A safety catch is a secondary closure (usually on a fine bracelet or necklace) that is used in case the primary clasp opens, preventing the loss of the jewelry. It is often a hinged, snapping loop that is permanently attached to one side of the clasp (often a box clasp), and, when the bracelet is closed, snaps onto the other side of the clasp.