Graphite Furnace Insulation board generally comes in two distinct forms:

  • Carbon bonded carbon fibre; common trade names include Americarb, Russcarb, Calcarb and Fibreform.
  • Rigidised graphite felt.


Online Furnace Services Ltd is the exclusive European agent for Americarb products. Americarb’s carbon fibre board, RCB-18, is a carbon fibre based ultra high temperature, high purity, low density graphite insulation board for use in demanding vacuum furnace applications at temperatures up to 2,600 C.
RCB-18 can be halogen purified to less than 20 PPM.
RCB-18 insulation board has excellent machining properties.

Graphite Furnace Insulation Cylinders

Insulation cylinder

Online Furnace supply both vacuum formed and rigid felt cylinders to suit circular hot zone requirements. More specialised foil/felt/foil constructions for sinterHIP units and CFC clad options are also available.

Typical applications include:

  • Vacuum heat treatment
  • Vacuum brazing
  • Hard metal sintering
  • Non-oxide ceramic production, e.g. aluminium nitride, silicon carbide, boron nitride, etc.
  • Precision casting units
  • Carbon fibre production