A mainspring including a spiral metal strip and a hooking area formed in an inner face of an inner end of the strip, the hooking area including at least one shaped portion and/or at least one cavity comprised in the inner face of the inner end.

A timepiece mainspring is accommodated inside a barrel, an inner end thereof is fixed to a barrel arbor included in the barrel, and an outer end thereof engages with an inner wall of the barrel. The timepiece mainspring includes a helical portion wound in a Bernoulli curve shape from the inner end in a free state having no applied load.

A flexible timepiece component, in particular for an oscillator mechanism or for a barrel of a horological movement, the component extending along a main plane (P) and including at least a part made of a composite material (1), the composite material (1) including a matrix (2) and a multitude of nanowires (3) distributed in the matrix (2), the nanowires (3) being juxtaposed, the matrix (2) including a material (4) for filling the interstices between the nanowires (3) to join them to each other, each nanowire (3) forming a solid one-piece tube, the nanowires (3) being disposed substantially parallel to an axis (A) substantially perpendicular to the main plane (P) of the component (6, 7).

The invention relates to a one-piece metal component including an electroformed metal body, the external surface of the body including, only over or to a predetermined depth, less trapped hydrogen than the rest of the electroformed metal body causing a hardening relative to the rest of the body in order to improve the wear resistance of the one-piece component while preserving a relative magnetic permeability of less than 10 and the ability to be driven or pressed fit.

The invention relates to a compacted and densified metal material comprising one or more phases formed of an agglomerate of grains, the cohesion of the material being provided by bridges formed between grains, said material having a relative density higher than or equal to 95% and preferably higher than or equal to 98%.

A timepiece spring, as a mainspring, made of austenitic stainless steel including a base formed of iron and chromium, thickness of the spring being less than 0.20 mm, and the spring including, by mass: chromium: minimum value 15%, maximum value 25%; manganese: minimum value 5%, maximum value 25%; nitrogen: minimum value 0.40%, maximum value 0.75%; carbon: minimum value 0.10%, maximum value 1.00%; the total (C+N) carbon and nitrogen content between 0.40% and 1.50% by mass; the carbon-to nitrogen ratio (C/N) by mass between 0.125 and 0.550; impurities and additional metals with the exception of iron: minimum value 0%, maximum value 12.0%; iron: the complement to 100%.

An amorphous alloy corresponding to the formula:

Co.sub.aNi.sub.bMo.sub.c(C.sub.1-xB.sub.X).sub.dX.sub.e wherein X is one or several elements selected from the group consisting of Cu, Si, Fe, P, Y, Er, Cr, Ga, Ta, Nb, V and W; wherein the indices a to e and x satisfy the following conditions: 55a75 at. % 0b15 at. % 7c17 at. % 15d23 at. % 0.1x0.9 at. % 0e10 at. %, each element selected from the group having a content 3 at. % and preferably 2 at. %, the balance being impurities.

A functional micromechanical timepiece assembly including at least a first component, including a first layer defining a first contact surface configured to come into friction contact with a second contact surface defined by a second layer, the second layer belonging, either to the first component, or to at least a second micromechanical component forming the assembly with the first component. The first and second layers each include carbon with at least 50% carbon atoms and, on the first and second contact surfaces, the layers have different surface crystalline plane orientations from each other.

A timepiece component includes a first silicon-based or ceramic-based part, and a second metal-based part. One surface of the first part is directly welded using laser-type electromagnetic radiation onto a surface of the second part in order to secure the parts without addition of material. A method for fabrication of a timepiece component for a timepiece includes forming a first silicon-based or ceramic-based part and a second metal-based part, mounting a surface of the first part on a surface of the second part, and welding, using laser-type electromagnetic radiation, the surface of the first part mounted directly on the surface of the second part, in order to secure the parts to each other without addition of material.

A torque-restoring element for an oscillator for a mechanical timepiece and having an oscillator frequency, said torque restoring element comprising a spiral spring body having a number N turnings with an inner terminal end for engagement with a rotational inertial element via a collet, and an outer terminal for engagement with a stationary cock element, and having a width, a height and a total arc length; wherein the spiral spring body includes a core formed from mono-crystalline silicon wafer oriented along the crystallographic axis <110>; and wherein the spiral spring body includes at least one peripheral coating of a material having a thermal elastic constant different from that of the core of the spiral spring body so as to maintain the oscillator frequency an oscillator including the torque-restoring element substantially insensitive to variations of ambient temperature.