NB SiC Thermocouple Protection Tubes

Nitride Bonded Silicon Carbide (NB SiC) Tubes

Nitride bonded silicon carbide (NB SiC) tubes offer an economical choice for thermocouple sensor OEMs.

These tubes can be produced to a large range of outer and inner diameters with several options for mounting. NB SiC does not contaminate non-ferrous melts, like cast iron tubes. It is also a popular choice in solutions for temperature measurement in heat treating furnaces.

  • Less than 12% porosity, with surface porosity of less than 1% +
  • Maximum service temperature of 1,450 °C
  • Economical choice
  • Non-ferrous furnaces
  • Heat treatment furnaces
Material Properties


Properties Unit Spec. Typical Values
Bulk Density g/cc >2.75 2.80
Apparent Porosity % <12 8
Surface Porosity % <1 0.5
Cold Modulus of Rupture (at room temperature) MPa >150 160
Hot Modulus of Rupture (at 1,400°C) MPa >140  180
Modulus of Elasticity GPa   240
Thermal Conductivity (at 1,000°C) W/m.K   20
Co-efficient of Thermal Expansion °C   4.4x10-6
Maximum Service Temperature °C   1,450


Refrax® 20E

Properties Unit Typical Values
Bulk Density g.cm-3 2.20
Apparent Porosity % 28
Modulus of Rapture ar 20°C N.mm-2 25
Thermal Conductivity at 1,000°C W/m-1.K-1 18.5
Abrasion Resistance - BS1902 cm-3 80


Cryston® 789A

Properties Unit Typical Values
Bulk Density g.cm-3 >26.2
Apparent Porosity % <16
Modulus of Rapture at 20°C N.mm-2 >165
Thermal Conductivity at 1,000°C W/m-1.K-1 15.5
Abrasion Resistance - BS1902 10-6/°C 5.1


* Technical data, right of modification reserved

  OD ID Length
N-Durance® 20 - 50 mm 8 - 26 mm Up to 1100 mm
Refrax® 20E 20 - 90 mm Wall 4 - 10 mm Up to 1600 mm
Cryston® 789A 25 - 40 mm 12 - 27 mm Up to 1500 mm




Data Sheets (TDS)
Specialty Ceramics Nitride bonded Silicon carbide Tubes

Saint Gobain Specialty Ceramics' products allow customers to solve tough problems in thermal and chemical processing, industrial metrology, temperature

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