Sapphire

Almath Crucibles offer a variety of sapphire tubes.

Sapphire tubes are ideal for protecting high-temperature thermocouples in corrosive environments, are 100% gas tight and will operate up to 2000C.

  • These tubes are not always held in stock – please check current delivery times with us if this is critical.
  • Different diameters and lengths are available on request. Please ask.
  • We can also offer custom-made sapphire products. Please request a quotation.
Markets & Applications
Semiconductor ManufacturingSubstrates, Wafers, Plasma Containment Tubes, Chamber Viewports, Lift Pins, Gas Injectors
OpticalLaser applications; high-performance optical windows including UV, NIR, IR; NMR Spectroscopy; windows, lenses, prisms, blanks
Military/AerospaceForward Looking Infrared (FLIR) windows, guidance systems, radiometry, missile nose domes, other general aerospace and marine applications
IndustrialGas and chemical analysis, thermocouples, insulators for RF and microwave applications, medical instrumentation and implants, wear parts including rods, bearings, blanks, friction plates
  • Chemical Resistance
  • Acids – Concentrated
  • Acids – dilute
  • Alkalis
  • Halogens
  • Metals
  • Electrical Properties
  • Dielectric constant
  • Dielectric strength (kV mm-1)
  • Volume resistivity @25 ̊C (Ohm-cm)
  • Mechanical Properties
  • Compressive strength (MPa)
  • Hardness – Knoop (kgf mm-2)
  • Hardness – Vickers (kgf mm-2)
  • Tensile modulus (GPa)
  • Physical Properties
  • Apparent porosity (%)
  • Density (g cm-3)
  • Refractive index
  • Useful optical transmission range (nm)
  • Water absorption – saturation (%)
  • Thermal Properties
  • Coefficient of thermal expansion @20-1000 ̊C (x10-6 K-1 )
  • Melting point ( ̊C)
  • Specific heat @25 ̊C ( J K-1 kg-1 )
  • Thermal conductivity @20 ̊C (W m-1 K-1 )
  • Upper continuous use temperature ( ̊C)
  • Good
  • Good
  • Good
  • Good
  • Good
  • 7.5-11.5
  • 15-50
  • >10(14)
  • 2100
  • 2000
  • 1600-1800
  • 350-390
  • 0
  • 3.985
  • 1.71-1.79
  • 150-5500
  • 0
  • 5.8
  • 2050
  • 750
  • 35-40
  • 1800-1950

View our full range of Sapphire products.

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