Materials
High-alumina and corundum material data.
Two alumina families cover most of what we make. The values below are typical properties for each material, and temperature and purity are given per grade.
Material datasheet
- High-alumina ceramic
- Al₂O₃ >85 %
- High-purity alumina / corundum ceramic
- Al₂O₃ 99–99.5 %
| Property | Unit | High-alumina | Corundum |
|---|---|---|---|
| Composition | |||
| Al₂O₃ content (%) | % | >85 | 99-99.5* |
| SiO₂ content (%) | % | <12 | <0.2 |
| Fe₂O₃ content (%) | % | <0.2 | <0.05-0.1 |
| Thermal and mechanical | |||
| Working temperature (°C) | °C | 1300–1450 | 1600–1800* |
| Hardness (Mohs) | 8 | 8-9 | |
| Water absorption (%) | % | <0.2 | ≤0.2 |
| Bulk density | |||
| Bulk density, slip cast (g/cm³) | g/cm³ | 3.6-3.7 | 3.7-3.9 |
| Bulk density, pressed or extruded (g/cm³) | g/cm³ | 3.5-3.65 | 3.65-3.8 |
| Bulk density, hot pressed (g/cm³) | g/cm³ | 3.5-3.7 | 3.7-3.85 |
| Rupture strength, room temperature | |||
| Rupture strength, slip cast (MPa) | MPa | 190 | 200 |
| Rupture strength, pressed (MPa) | MPa | 140 | 150 |
* Stated per SKU: the grade and maximum temperature of each part are confirmed in its quotation.
See our ISO 9001 certificate and lab test report
Drawing says C 799, C 610 or KER 710? What the ceramic grade classes mean
Compare alumina density and properties by purity: supplier data, our forming-method ranges and what to put on the drawing.
Notes on these values
Corundum grades
Our standard grade is C799 alumina, 99.5% Al₂O₃. Where a drawing names C 610, we supply 95% white alumina. The property data apply to the 99–99.5% material, and for 95% the properties are confirmed per part.
Per SKU
Purity and maximum temperature are stated for each product, and each part's grade and maximum temperature are confirmed in its quotation.
Your quotation
Values are typical. We confirm the grade, dimensions and tolerances in each quotation. Our yearly lab reports are available on request.
Properties
What alumina ceramics are chosen for
Which of these apply depends on the grade and the part.
- High-temperature resistance
- High mechanical strength
- Good thermal conductivity
- Thermal-shock resistance
- High softening temperature
- High-temperature electrical insulation
- High-frequency electrical performance
- Acid and alkali resistance
- Chemical corrosion resistance
- Wear resistance
- Low contamination for appropriate high-purity grades
Other materials
Also available on request
We also make parts in these materials. Ask for property data in your quote request.
- Mullite ceramic
- Steatite ceramic
- Cordierite ceramic
- Wollastonite ceramic
- Chrome-corundum ceramic
Request a quote
Not sure which grade you need? Tell us the temperature and atmosphere.
Tell us the dimensions, grade and quantity. We confirm the grade, dimensions and tolerances in each quotation. Our yearly lab reports are available on request.
- Custom parts, usually from
- 100 pcs
- Samples for approval
- 5–10 pcs
- Production, usually
- 25–30 days
- Standard sizes from stock, small to bulk orders
- ~3–7 days