The main purpose of watch jewels is to minimise the metal’s friction on the jewel. By withstanding relatively high pressures, in the short term they help avoid the kind of jamming that would normally occur between two metal parts.
Since its foundation, the company has supplied jewels to some of the most prestigious watch manufacturers, enabling it to acquire the know-how from which it benefits today in other sectors.
STONES – SAPPHIRES
Monocrystalline sapphire has a unique combination of physical, mechanical and chemical properties that give it an extremely wide range of applications: high mechanical strength, high thermal stability, high optical transmission in the ultraviolet, visible and infrared range, very high resistance to abrasion, chemical inertia, zero porosity, very high insulation, the greatest hardness after diamond.
Structure cristalline | monocristal hexagonal rhomboédrique |
Composition | Al2O3 |
Pureté | 99.99% |
Principales impuretés | Na2O, Si, Ca, Fe, Ga, Mg, Ti, Mn, Pb, Cu, Zn, Ni |
Clivage | conchoïdal |
Densité | 3.99 – 3.98 |
Densité de dislocation | 109 – 108/m2 |
Dureté | Mohs 9 K | noop 2200 face // axe C Knoop 1800 face ^ axe C |
Module d’élasticité | 4.4·1011 | Pa à 300 K |
Module de rupture | 4.0·108 | Pa à 300 K |
Résistance à la compression | 2.1·109 | Pa à 300 K |
Résistance à la traction | 1.9·108 | Pa à 300 K |
Constante de Poisson | 0.3 |
Température de fusion | 2320 K |
Point de ramolissement | 2070 K |
Chaleur spécifique | 7.5 x 102 J / kg·K à 300 K |
Conductivité thermique | 40 W / m·K ^ à 300 K |
Dilatation thermique | 6.2·10-6 / K // axe C 5.4·10-6 / K ^ axe C |
Attaque acides et alcalis | 0 à 570K |
Porosité | 0 |
Constante diélectrique | 10.6 champ électr. // axe C à 300K 8.6 champ électr. ^ axe C à 300K |
Résistivité électrique | 109 Ω·m à 770K 104 Ω·m à 1270 10 Ω·m à 2270K |
Indice de réfraction nD à 0.5893μm | 1.760 face // axe C 1.769 face ^ axe C |
Dispersion chromatique (nF – nC) λ | 0.011 λλF=0.4861μm λC=0.6563μm |
Transmission visible | Excellente |
Transmission infrarouge | 85% 0.75 – 5μm 70% 5.5μm 50% 6μm |
Transmission ultraviolet | 80% 0.4 – 0.3μm 60% 0.28μm 50% 0.2μm Epaisseur du disque 1μm |
Incabloc SA
Rue de la Paix 129
CH-2301 La Chaux-de-Fonds
lyre@incabloc.ch
T. + 41 32 924 00 05
F. + 41 32 924 00 06
support jewel «PA»
flat olive jewel «GO»
domed jewel «B»
domed olive jewel «BO»
flat jewel with two recesses «G2C»
flat olive jewel with two recesses «G2CO»
semi-flat jewel «MG»
semi-flat olive jewel «MGO»
domed semi-flat jewel «MGB»
domed olive semi-flat jewel «MGBO»
flat jewel «G»
olive support jewel «PAO»
domed olive support jewel «PABO»
support jewel with polished ribbon «PARP»
domed support jewel with polished ribbon «PABRP»
support jewel domed on both sides with polished ribbon «PAB2XRP»
support jewel domed on both sides «PAB2X»
endstone «CP»
domed endstone «CPB»
endstone domed on both sides «CP2B»
domed endstone with off-centre recess «CPBCD»
endstone
recess + domed «CPCB»
pin «GOU»
flat jewel with cone-shaped recess «GC»