Magnesium Oxide is used to electrically isolate and mechanically support the thermoelements of a thermocouple. The metal sheath is typically reduced in diameter to compact the oxide powder or crushable oxide insulators around the thermoelements or wires. In order to be suitable for this purpose, the materials shall meet certain criteria for purity and for mechanical and dimensional characteristics. The higher purity also improves insulation resistance at high temperature.

AVAILABLE

Heater Grade MgO Winding Cores
Cartridge Wind Cores, Cartridge Heater Cores, Swageable Cores, Swageable Insulators

Thermocouple, MI Cable, RTD
Crushable Insulators, Crushable Preform, Swageable Perform, Thermocouple Insulators, MIMS Insulators Beads

CHEMICAL PROPERTIES

Magnesium oxide (mgo) 99.40%(mass) min

Impurity Concentration, %(mass)
Calcium oxide (CaO) 0.35 max
(Aluminum Oxide) Al2O3 0.15 max
Iron Oxide (Fe2O3) 0.04 max
Silica (SiO2) 0.13 max
Carbon (C) 0.02 max
Sulpher (S) 0.005 max
Boron (B) 0.0035 max
Cadmium (Cd) 0.001 max
B+ Cd 0.004 max

Also available 96% and 98% purity

PRODUCT SPECIFICATION

  • OD sizes from (0.09 mm – 46 mm)
  • Round, Oval, Triangular holes
  • Complex hole configurations
  • Excellent camber properties

  • Customer specified hardness – strong engineering support

  • Highly equipped testing lab for quality check up

OUTSIDE DIAMETER TOLERANCES

Nominal Insulator OD OD Tolerances
0.25 to 1.48 mm (0.010 to 0.058 in.) ± .05 mm (0.002 in.)
1.49 to 6.33 mm (0.059 to 0.249 in.) ± .08 mm (0.003 in.)
6.34 to 9.51 mm (0.250 to 0.374 in.) ± .10 mm (0.004 in.)
9.52 to 12.70 mm (0.375 to 0.500 in.) ± .15 mm (0.006 in.)
12.71 mm (0.501 in.) and larger   ± 1.6 %

(As per standard ASTM 1652)
NOTE: Tolerance available as per DIN40680

HOLE DIAMETER TOLERANCES

Nominal Insulator Hole Diameter Hole Diameter Tolerances
0.18 to 0.26 mm (0.007 to 0.010 in.) ±.038 mm (0.0015 in.)
0.27 to 1.51 mm (0.011 to 0.059 in.) ±.05 mm (0.002 in.)
1.52 to 2.52 mm (0.060 to 0.099 in.) ±.08 mm (0.003 in.)
2.53 to 3.79 mm (0.100 to 0.149 in.) ± 4 %
3.80 mm (0.150 in.) and larger ± 5 %

(As per standard ASTM 1652)