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)