Property Designation Unfired Fired Color   Grey Buff-Tan Hardness Mohs 2 6 Water Absorption % 2.7 2.5 Specific Gravity   2.5 2.3 Tensile Strength PSI 1,000 3,000 Compressive Strength PSI 11,000 25,000 Flexural Strength PSI 4,000 10,000 Maximum Operating Temperature Under Non Loading Conditions °C 650 1,100 °F 1,200 2,000 Linear Coefficient Of Thermal Expansion (@25 °C - 100 °C) x10-6 /°C 2.5 2.9 (@25 °C - 600 °C) x10-6 /°C 3.1 3.6 Dielectric Strength (1/4" Thick) VOLTS/MIL 80 100 Dielectric Constant At 25 °C & 1 mhz 5.8 5.3 Loss Factor At 25 °C & 1 mhz 0.06 0.05 Te Value Temp °C @ which one cm3 of material has a mega-ohm of resistance   700 NOTE: THE INFORMATION IN THIS DATA SHEET IS FOR DESIGN GUIDANCE ONLY. FORMING METHODS AND SPECIFIC GEOMETRY COULD AFFECT PROPERTIES. SLIGHT ADJUSTMENTS CAN BE MADE TO SOME OF THE PROPERTIES TO ACCOMMODATE SPECIFIC CUSTOMER REQUIREMENTS. MOST OF THE DENSE MATERIALS IN THE TABLE ARE RESISTANT TO MECHANICAL EROSION AND CHEMICAL ATTACK.