Fiberglass Cables | Caviterm

Fiberglass Cables: A Complete Guide to Characteristics, Uses, and Performance

January 26, 2026

Fiberglass cables are among the most reliable solutions for high-temperature applications in industrial environments and sectors that require electrical and mechanical stability even under extreme conditions.

Caviterm products are designed to meet these needs, thanks to selected raw materials, careful production processes, and constant quality control.

What are fiberglass cables

Fiberglass cables are electrical conductors insulated and coated with high-resistance fiberglass spirals and braids. Depending on the conditions of the various applications, fiberglass may be the sole insulation or may also be combined with other materials such as silicone rubber and PTFE. The correct combination of these insulating materials allows the cable to maintain integrity and performance even when subjected to intense heat, vibrations, and extreme conditions in general.

Fiberglass is composed of micro-filaments compacted and braided together to form an insulation that is robust, lightweight, and not subject to thermal degradation as occurs with traditional plastic materials.

To fully understand how they work and what they are capable of, it may also be useful to explore the insulation class of electrical cables, which defines the thermal and performance limits of insulants.

Difference between fiberglass and other insulating materials

Compared to PVC, silicone rubber, or PTFE, fiberglass offers significant advantages for specific applications:

  • Greater thermal resistance: essential for all applications where the maximum temperature of electrical cables is a critical parameter.
  • Safer fire behavior: fiberglass by its nature does not propagate flame.
  • Greater durability in harsh environments: ideal for heavy industries, furnaces, thermal systems, professional tools, and measuring equipment.

Caviterm cables leverage this material to ensure consistent performance where conventional solutions cannot function.

Main properties of fiberglass cables

Fiberglass cables are chosen primarily for three types of performance:

  • Thermal resistance: Fiberglass coatings withstand continuous high temperatures, and special versions with additional treatments can reach even higher values. This makes them suitable for applications where heat is a constant factor, such as electrical resistances, heating systems, and thermocouples.
  • Electrical insulation: Fiberglass has stable dielectric behavior even when exposed to heat, ensuring safety and signal continuity.
  • Chemical and mechanical robustness: The cables are resistant to oils, solvents, industrial greases, and abrasion. Even in the presence of vibrations, they maintain their integrity without suffering structural damage.

Types of fiberglass cables and applications

Caviterm produces several families of fiberglass cables, designed to meet specific needs:

  • High-temperature cables: Used in industrial equipment, electric furnaces, resistances, heating systems, and thermal control instruments. For a general overview of thermal insulation in wiring, it may be useful to consult the complete guide to insulating electrical cables from heat.
  • Thermocouple cables: Designed for the accurate transfer of temperature signals. Fiberglass ensures stability even in very hot environments.
  • Cables with combined insulation (fiberglass + other sheaths): In some cases fiberglass is combined with silicone, PTFE, or metal coatings to achieve additional properties, such as waterproofing or resistance to corrosive substances.

Advantages of fiberglass cables over other materials

Caviterm fiberglass cables offer numerous advantages:

  • Longer service life in challenging environments
  • Maintained properties even at high temperatures
  • Excellent performance-to-cost ratio for high thermal stress applications
  • Low flame propagation
  • Electrical stability even with temperature fluctuations

How to choose the right fiberglass cables

To identify the most suitable cable for your needs, it is useful to consider:

  • Working temperature: continuous, peak, and environmental conditions.
  • Rated voltage: based on the system or device.
  • Required flexibility: some applications involve challenging bending radii.
  • Presence of chemical substances: oils, solvents, high humidity, vapors.

Caviterm can support the selection process thanks to technical expertise and a complete catalog of standard and customized solutions.

Frequently asked questions about fiberglass cables (FAQ)

How resistant is fiberglass in cables?

It is extremely resistant to heat and abrasion. When combined with other insulants and the correct impregnating agent, it is also optimal against chemical agents. It maintains integrity and properties even beyond 400°C, making it suitable for conditions that would damage other insulants.

When are fiberglass cables used?

They are used when the working environment features high temperatures, presence of flame, and moderate vibrations. Ideal for furnaces, resistances, thermocouples, motors, and industrial equipment.

Are fiberglass cables dangerous or toxic?

No. Fiberglass is not toxic and does not emit harmful substances at normal operating temperatures. It does not burn and does not produce dangerous fumes like some plastic materials.

How long do fiberglass cables last?

Their service life depends on correct operating conditions and is in any case always longer than that of plastic insulants.

How much do fiberglass cables cost?

The cost varies depending on cross-section, conductor type, number of cores, and any additional coatings. In general, they have a competitive price compared to other high-temperature cables, especially considering their longevity.