Technical Ceramics

Extrusion Materials

Luminex™ - Magnesium Oxide (Magnesia)

Our Luminex™ Magnesia is renowned throughout the industry for its quality and consistency. Extruded Magnesia (MgO) is used primarily in heat engineering applications such as cartridge heaters and thermocouples, due to its unique properties having both excellent thermal conductivity and electrical insulation at temperatures of up to 1200°C.

In most applications the extruded Magnesia is slipped around heater cables and sheathed in metal tubes before being crushed to its ultimate size within the cable. In this state, the cable is able to be wound or bent into shape without loss of the ceramic’s insulation or conductivity properties.

Typical Luminex™ Applications

  • Sheath and high wattage cartridge heaters
  • Metering instrumentation
  • High temperature cabling
  • Thermocouples

We offer three grades of Luminex™ tailored to meet the needs of a range of applications:

Luminex™ 970

A minimum 96% pure Magnesium Oxide (typically 99%) used for a variety of electrical insulation qualifications in domestic and industrial environments.

Luminex™ 993

An ultra pure Magnesium Oxide with a minimum purity of 99.45% and above, low water absorption properties, high volume resistance and minimal sulphur content, this grade is well suited to applications such as micro cartridge heaters and thermocouples.

Luminex™ 998

A 99.45% pure magnesium oxide for use in applications in which electrical properties need to be maintained at high temperatures, in particular high electrical resistance can be maintained up to 1100°C.  This material meets the ASTM E1652 standard.

Aluminium Oxides (Aluminas)

Extruded Aluminas offer a combination of good mechanical and electrical properties. Available in a range of purities from 96% to 99.7%, Aluminas are well suited to a wide range of applications from resistors to specialist medical devices.

The material characteristics of Aluminas allow for extremely small extrusions, highly complex geometries and excellent surface finishes. Additionally Alumina, as a fully dense material, can be processed to further improve surface finish or to meet tighter dimensional tolerances.

Typical Aluminas used in extrusions are:

Hilox™ 961 Alumina 

A brown coloured 96% Alumina, with exceptional wear properties, typically used for applications such as pump shafts.

Hilox™ 965 Alumina 

A white, minimum 95% Alumina, for applications requiring good surface finish as well as the excellent mechanical and electrical properties typical of aluminas.


A 99.5% high purity Alumina, excellent for the smallest extrusions or in applications in which exceptional surface finish is required.


A Magnesium Silicate offering an economical solution for product needing good high temperature electrical resistance for components without a requirement for the high strength properties of Alumina. Typically for use only in high volume applications.

Specialist and Custom Made Extrudable Materials

We also offer a range of additional materials to meet even the most specific and specialist requirements of your application. If your application can not be satisfied by any material in our current range then our ceramicists are also able to develop bespoke materials to match such defined requirements as porosity, strength, permeability, or electrical properties.

Example Specialist Materials:

  • Silica
  • Spinel
  • Zirconium Oxide (Zirconia)
  • Hafnium Oxide (Hafnia)