These are single or multicore cable suitable for extreme temperature conditions. They find their application in steel industries, cement industries, glass industries, ship buildings, and aviation. SiF and SIFF are flexible single-core cables with tinned copper conductor and silicon insulation.

Similarly, multicore SiHF cables have silicon rubber insulation and sheath. These cables can withstand a continuous temperature of -50°C to +180°C and are also available with glass fibre braiding as SiF-GL & SiD-GL.