A Fire Brick, Firebrick, Or Refractory Brick Is A Block Of Refractory Ceramic Substance Used In Lining Furnaces, Kilns, Fireboxes, And Fireplaces.

A Refractory Brick Is Built Originally To Endure High Temperature, But Will Also Usually Have A Low Thermal Conductivity For Higher Strength Energy. Normally Dense Firebricks Are Utilized In Applications With Extreme Mechanical, Chemical, Or Thermal Stresses, Such As The Inside Of A Wood-Fired Kiln Or A Furnace, Which Is Subject To Abrasion From Wood, Fluxing From Ash Or Slag, And High Temperatures.

In Other, Less Hard Conditions, Such As In An Electric Or Natural Gas Fired Kiln, More Permeable Bricks, Usually Known As "Kiln Bricks" Is A Valid Choice. They Are Weaker, But They Are Much Lighter, Easier To Form And Insulate Far Better Than Dense Bricks. In Any Matter, Firebricks Should Not Lose Their Strength So It Should Hold Up Well During Rapid Temperature Changes.