We supply various kinds of perfect optical sapphire crystals including flat surface , curved surface , spherical surface , multi surface , cylindrical surface , box type , and some other very special style .
We use the Level A raw material which have excellent transmittance (85% , it come up to 93% after make anti-reflective coating) ; high hardness (Mohs 9 which only less than diamond ) ; high purity quotient (the chemical purity is 99.995%) . The Density of our sapphire material is 3.98-4.1g/cm³, and it have below physical properties:
● Compressive Strength: 21000 kg/ cm²
● Tensile Strength: 1900kg/ cm²
● Bending Strength: 4000kg/ cm²
● Refractive Index: parallel optical axis 1.769, vertical optical axis 1.76
● IR Transmittance: 83%
● Melting Point: 2050℃
● Softening Point: 1800℃
● Specific Heat: 0.18cal/g. ℃; 25℃
● Expansion Coefficient: parallel optical axis 6.7x10-6/℃, vertical optical axis 5.0x10-6/℃
● Heat Conductivity: 0.09cal/sec.cm℃; 25℃
These crystals are widely used for watch surface , watch case, watch bezel, watch dial , watch movement , mobile lens , camera lens , jewellery , medical equipment , artware , substrate of LED etc .
