Abstract: The watch case comprising a middle (2) containing a lining (4) and a back (9) detachably mounted in a lower opening of the middle by means of a pressure device. A band (12) of synthetic material constituting a seal is formed on the periphery of the opening, that band being made in one piece with the lining and connected to it by portions of synthetic material crossing appropriate passages (15) of the middle. The side walls (16) of the opening are at least partially devoid of lining and they work together with opposite surfaces (17) of the back in order to assure pressure coupling of the latter and compression of the band (12).

Abstract: A watch case and means for fastening a viewing crystal to the upper opening of the watch case. The upper opening is provided with projections and the viewing crystal is provided with a flange for engaging the underside of the projections, on at least a part of its thickness. The viewing crystal is introduced freely into the upper opening and rests on a flexible element. Fastening is accomplished by pushing the piece of glass to compress the flexible element and engaging the flanges under the projections by rotation or movement in the case of the viewing crystal. The invention is particularly advantageous for monopiece cases.