Abstract: The surface of metallic appearance of the timepiece dial has a visible morphology corresponding to that of mother-of-pearl. According to the process for manufacturing this dial, a mother-of-pearl sheet is subjected to a sandblasting operation, to give its surface finish the morphology of mother-of-pearl, this surface is cleaned and coated with a layer of metallic appearance.

Abstract: The surface of metallic appearance of the timepiece dial has a visible morphology corresponding to that of mother-of-pearl. According to the process for manufacturing this dial, a mother-of-pearl sheet is subjected to a sandblasting operation, to give its surface finish the morphology of mother-of-pearl, this surface is cleaned and coated with a layer of metallic appearance.

Abstract: Tools having a surface coating of at least one compound containing at least one element from the main group of Group VI of the periodic table and at least one element from the subgroup of Groups V and VI of the periodic table. The coating may consist of molybdenum disulfide, for example. These tools are superior to conventional hard-solid covered tools in various respects and may be milling cutters, for example, which have an excellent edge life, even more than six times as long. Moreover, the machined surfaces have substantially less surface roughness and make it possible to work with higher feeds.

Abstract: A one-way check valve for pressurized fluid is described which comprises the following elements: a cylindrical envelope (1) provided with a chamber (2) having a fluid inlet passage (3) at its base and a fluid outlet passage (4) at its top end, a mobile sphere (5) which moves inside the chamber (2), under the effect of the pressure exerted by the fluid, from a closed position to an open position or vice-versa, and a ring (6) firmly fixed to the base of the envelope (1) and serving as a seat for the mobile sphere (5) in the closed position, the upper part (7) of the ring (6) being shaped so as to present a spherical or conical contact surface (8), the upper part of the chamber (2) having stops (9) separated by passages (10) leading into the fluid outlet passage (4), the lower part of each of the stops (9) being shaped so as to present a spherical or conical contact surface (11), and the mobile sphere (5) being retained by the said stops (9) in the open position, and the envelope (1), the mobile sphere (5) and t