By a controlled continuous melting of ultra-pure Al2O3 powder, a monocrystalline rod (" boule") can be obtained. It has the properties of the best alumina ceramics; the sapphire items can also have very good optical properties and they are scratch-proof, corrosion and high temperature resistant. Due to the non porous structure they are highly polishable and very high precision in very small sizes is obtained (i.e. 35/40 m diameter holes).

Cup jewel with hole


Cone jewel width hole




All our sapphire and ruby items are available also mounted.

1. Nickel-plated brass with sapphire hole bearings.
2. Nickel-plated brass with bored ruby ball.
3. Brass mount for compasses with agate bearing.
4. Stainless steel nozzle width bored sapphire.
5. Sapphire needles for technographs.

Technical data
Density (g/cm3)	-	3,99
Flex. strength (MPa)	-	350
Compress. strength (MPa)	-	2100
Young modulus	-	430
Vickers hardness (500 p)	-	1900
Thermal expansion (10-6K-2)	20-900 C	5,4
Thermal conductivity (W/m-K)	20-100 C	41
Resistivity (ohm-cm)	20 C	1016
"	600 C	109
Max operating temp. (C)	-	1700