• Heat resistance: Can withstand temperatures from about 1,000 °C up to 1,800 °C depending on grade.
• Composition: Typically made from alumina, silica, magnesia, or other refractory materials.
• Density & insulation: Available in dense (heavy) types for structural strength and insulating (lightweight) types for thermal insulation.
• Shape & size: Usually rectangular like normal bricks, but can also be shaped for specific furnace or kiln designs.
• Durability: Resistant to spalling (cracking due to heat changes) and chemical corrosion from slags, ash, or gases.