Non-asbestos. Bonds and seals metal to-metal and metal to masonry joints under 1/8 in. Durable as firebrick when heat cured. Resists temperatures up to 1482 deg C (2700 deg F). Used to repair wood or coal stoves, furnaces, fireplaces and flues. Prevents air and gas leaks in flue and chimney joints. Meets or exceeds ASTM C 199 Pier test.