A bezel cup — known in British trade usage as a collet cup — is a preformed metal blank, open at the top and closed or open at the base, manufactured to receive a calibrated gemstone within a bezel setting. Rather than fabricating a bezel from scratch by bending flat wire or strip around a stone, the jeweller begins with a ready-made cup whose walls are already sized and shaped to the gemstone's girdle outline. Once soldered to a mounting or shank, the stone is seated and the projecting rim is pressed or burnished inward over the girdle to secure it. Bezel cups are among the most widely used bench findings in production jewellery manufacture, valued for the consistency and time-saving they bring to high-volume work.

Construction and Materials

Bezel cups are stamped or drawn from sheet metal in standard gauges, typically between 0.3 mm and 0.5 mm wall thickness for fine silver or gold alloys. Fine silver (999) is the traditional choice for hand-setting because its softness allows the rim to fold cleanly without cracking; gold alloys — most commonly 18-carat yellow, white, or rose gold — are used where the cup must match the mounting's metal. Platinum cups, though less common as off-the-shelf findings, are produced for high-end commissions. The base of a cup may be solid (a closed collet, which reflects light back through a transparent stone) or pierced (an open collet, which allows light to pass through and is preferred for faceted transparent gems). Some cups are supplied with a serrated or scalloped rim to facilitate even folding.

Sizes, Shapes, and Standards

Manufacturers produce bezel cups in the full range of calibrated gemstone shapes: round, oval, cushion, marquise, pear, emerald-cut (octagonal), and princess-cut (square), among others. Sizing follows the millimetre calibration system standard in the trade — a round cup designated "6 mm" is designed to accept a stone with a girdle diameter of approximately 6 mm. Tolerances are tight enough for production work but the jeweller is expected to verify fit before soldering, since slight variation in stone cutting or cup drawing can require minor adjustment with a bezel-opening tool or burnisher.

Use at the Bench

The workflow is straightforward. The cup is first fitted dry to the stone to confirm the girdle sits at or just below the rim. It is then soldered — using hard or medium solder, depending on subsequent operations — to the mounting. After any additional soldering steps are complete, the stone is placed and the rim is worked down in stages using a bezel pusher or rocker, moving around the circumference in opposing passes to avoid distorting the wall. A burnisher is used for the final smooth-over. The closed base of a solid cup can be pierced after soldering if the design requires a window beneath the stone.

Trade Context

Bezel cups are a staple of jewellery findings catalogues from suppliers across the United Kingdom, North America, and continental Europe. They are sold individually or in bulk packs sorted by shape and size, and are available in base metal (brass or copper) for student and prototype work. In the British trade the term collet cup remains current alongside bezel cup, reflecting the older English usage of collet for any encircling stone setting — a term that survives in watchmaking as well. For bespoke or artisan work, some bench jewellers still prefer to raise their own bezels from strip, arguing that hand-formed walls can be tuned precisely to an individual stone's girdle profile and thickness; for production runs or student exercises, the preformed cup is the practical standard.