95% AI2O3 Pink Aluminium Oxide Ceramic
Stress relieving interlocking heatermat beads

Stress Relieving Interlocking Insulators for Pre and Post-Heating

In welding large structures, pipe works and reaction vessels etc. it is a common practice to locally employ electrical heating devices to raise the temperature of the metal sections prior to welding and to control the sudden fall in temperature after the area is welded.

Jyalox ceramic has excellent electrical properties such as insulation and heat dissipation which ensure safe operation, quick and proper heating of area at the elevated temperatures.

The electrical device is in the form of flexible heater mat, constructed with alumina ceramic interlocking beads. The electric heating elements are supported by ceramic beads which insulate the device from the strucutre being welded.

Flexible electrical heating mats find the widest use in stress relieving applications, as the interlocking pattern of ceramic beads allow maximum flexibility to the mat, to cover the heating element properly from exposure to the area required to be heated up, such as concave, convex and flat surfaces of vessels, pipes etc.

Jyalox ceramic bead insulators available for construction of stress relieving flexible electrical heater mats.

Several mats can be connected together to cover large surface areas of vessels, pipes etc., required for stress relief treatment.

Jyalox ceramic stress relieving bead insulators are mechanically tough, strong and wear resistent to withstand abuse of rough handling of heater mats commonly experienced while in use in heavy construction industry.


All Dimensions are in mm : Tolerances which are not specified are as per DIN 40680.

Normal tolerances are
  • Upto 4 mm ± 0.15 mm
  • From 6 to 8 mm ± 0.25 mm
  • From 4 to 6 mm ± 0.20 mm
  • Above 8 mm ± 3%
Chemical Composition
AI2O3 95.00 %
SiO2 2.0 %
MgO 1.0 %
Cr2O3 0.5 %
Others 1.5 %
Thermal Properties
Co efficient of Linear Thermal expansion (Room temperature to 1000 °C) 8.5 x 10-6 K-1
Thermal Conductivity (@Room Temperature) 23 - 24 W/m K
Max Temperature of use (No Load Condition) 1500 °C (2732 °F)
Electrical Properties
Dielectric strength (@Room Temperature) 15 - 23 kV/mm
Dielectric Constant (@Room Temperature : 1 MHz) 8.7 - 9.0
Dissipation Factor (@Room Temperature : 1 MHz) 0.0003
Volume Resistivity (@Room Temperature) >1014 Ω.cm
Physical Properties
Colour Pink
Surface Finish Smooth
Density 3.80 ± 0.05 g/cm3
Bulk Density 2.25 ± 0.05 kg/ltr
Porosity Nil
Water absorption 0 %
Hardness on Moh's scale 9 +
Hardness on Vicker's scale 1425 Hv5
Flexural Strength (@Room Temperature) 325 MPa
Compressive Strength (@Room Temperature) 2150 MPa
Young's Modulus 310 GPa