Ceramic Fiber vs Glass Fiber for High-Temperature Insulation

Where each fiber belongs

Both ceramic (alumina-silicate) and glass (E-glass / C-glass) fibers insulate, but their service ceilings are very different.

Glass fiber textiles

• Continuous use up to ≈ 550°C (standard E-glass); treated or high-silica grades reach higher.
• Good for lagging, welding blankets, expansion-joint cloth and general thermal wraps.
• Lower cost, easier to handle; remains flexible after repeated heating.

Ceramic fiber textiles & blanket

• Continuous use up to ≈ 1000–1260°C depending on grade.
• Used in furnace linings, kiln seals, molten-metal splash protection and high-temperature gaskets.
• Higher cost; choose when glass fiber would soften or melt.

Selection rule

If the surface stays below ~500°C, glass fiber is the economical choice. Above that, specify ceramic fiber. For thermal shock and molten-metal contact, ceramic fiber is mandatory.

See our product catalog for ceramic fiber blanket, ceramic textiles and glass fiber cloth.