Grid bricks are made of engineered fire clay, which is a mix of fire clay, clays, shale and reactive minerals such as iron oxide. The mix is prepared with great precision and skilled labor in order to ensure that the finished bricks have proper strength and wear resistance. On a typical grid brick, the surface has a distinct latticework design, which gives it greater strength and durability.
The size of grid bricks varies depending on the application. For instance, refractory grid bricks for use in furnaces and kilns measure about 8 by 4 inches, which is significantly larger than the usual bricks found in civilian construction. These bricks are arranged in a latticework or grid pattern, which allows hot gases and smoke to pass through them easily.
Grid bricks can hold up to very high temperatures, depending on the composition and quality of the fire clay mix. The bricks are quite dense, which increases their temperature resistance and their ability to absorb heat. This ensures that furnaces and kilns—which reach temperatures of up to around 1,400°C—can be insulated effectively with grid bricks.
The most common type of furnace used in many industries is the rectangular type. As such, this type of brick is usually manufactured in slightly longer and wider dimensions, with length and width being around 8 to 10 inches. These bricks are usually thicker than 4 inches, which is the size of most standard bricks.
Grid bricks are also sold in various sizes to accommodate different furnace designs and layouts. For example, arch-shaped furnaces usually require longer and narrower bricks, while some types of domestic furnaces require shorter, wider bricks. The weight of the bricks vary too, with some weighing as little as 5 pounds and others as much as 10 pounds.
Grid bricks are also commonly used in kilns, where temperatures can reach up to 800°C. The difference between grid bricks for use in kilns and for furnaces is that kiln applications require bricks with a smoother surface, so that glass and ceramic objects can be fired without their glazing or decorations being damaged.
The grid design of the bricks also helps keep them from cracking and crumbling during an uneven or prolonged exposure to high temperatures. This makes them the ideal choice for use in furnaces and kilns, where materials are subject to very high temperatures that can damage lesser quality bricks.
