9 In. X 4-1/2 In. X 1-1/4 In. Medium-duty Firebricks (3 Per Box)

The main ingredient in firebricks is fireclay, which contains mostly alumina and silica, elements capable of withstanding high temperatures. Hard bricks are available in several grades, depending on their composition and properties, which determine the application of the product. Proper selection of the appropriate grade is critical. Our firebricks are rated medium-duty and have a temperature rating to 2700°F maximum and a high thermal shock resistance. Medium-duty firebricks are standard in most high efficiency wood burning appliances. Uses include backup linings, lower-temperature ceramic kilns and chimneys, and contains 34-38% alumina.