Case

No standards body, museum or law opened for this entry defines what a watch case is. ISO's own vocabulary for the trade, ISO 6426-2:2026, Horological vocabulary — Part 2: Technical and commercial definitions, edition 3, published in February 2026 by ISO/TC 114/SC 9, says of itself only that it "defines the principal terms used in horology". Only that scope statement is public, so whether "case" is among those principal terms cannot be checked here.

ISO writes about the case constantly without any public text saying what it is. ISO 23160:2011, Watch cases and accessories — Tests of the resistance to wear, scratching and impacts, "specifies tests for the evaluation of the resistance of watch cases and their bracelets to wear, scratching and impacts occurring when wearing the watch". ISO's own news release on water-resistant watches puts the case at the centre of the claim a buyer reads: if a watch is marked water resistant to 30 metres, "this means that for all aquatic activities down to a depth of 30 meters, the watch case should not leak." The case is the thing tested and the thing that must not leak. Whether ISO 6426-2:2026 defines it among its "principal terms" cannot be checked here, because only that standard's scope statement is public.

The Swiss industry's own norms come closer and still stop short of a public definition. The list of available NIHS standards published by the Federation of the Swiss Watch Industry, valid from April 2026, includes NIHSG 60-01, Boîtes – Terminologie (cases, terminology; first issued 1967, revised 2022). A terminology norm for the watch case therefore exists; as with the ISO vocabulary, only its title is public, so its wording is not quoted here.