GN500 High Temperature Industrial Furnace Wire (500°C)
The GN500 is an ultra-high temperature furnace wire engineered for continuous service at 500°C in the demanding internal wiring environments of industrial furnaces, kilns, ceramic ovens, melting furnaces, and high-temperature industrial heating equipment. Where silicone rubber wire reaches its practical limit at 200°C and standard mica-glass wire is rated to 450°C, the GN500 extends usable service temperature to 500°C through an optimised mica tape insulation system combined with a high-temperature treated fiberglass braid outer covering.
The mica tape insulation layer provides the core high-temperature performance: mica is a naturally occurring mineral with a melting point exceeding 700°C, and it retains its electrical insulating properties at temperatures far beyond the capability of any organic polymer insulation. Even in the event of a thermal overload or localised hot spot above the rated temperature, mica insulation maintains electrical isolation and prevents short circuits — a critical safety property in furnace wiring where a wire failure can cause equipment damage or fire.
The treated fiberglass braid outer covering provides mechanical protection during installation, resistance to abrasion from furnace structure contact, and additional thermal insulation mass. The nickel-plated copper conductor option extends oxidation resistance at elevated temperatures, maintaining stable conductor resistance over the full service life of the wire in oxidising furnace atmospheres.
Technical Specifications
| Parameter | Specification |
|---|---|
| Product designation | GN500 |
| Temperature rating | 500°C continuous |
| Voltage rating | 500V AC |
| Conductor material | Nickel-plated copper or bare copper, solid or stranded |
| Insulation | Multi-layer mica tape (non-extruded) |
| Outer covering | Treated fiberglass braid (silicone varnish or PTFE finish) |
| Available cross-sections | 0.5 mm² – 16 mm² |
| Available AWG range | 20 AWG – 6 AWG |
| Flame rating | Horizontal flame (self-extinguishing) |
| Standard | GB/T 13033, IEC 60800 (reference) |
| Color options | Natural fiberglass (off-white / beige), custom wrap color |
| Packaging | 50 m / 100 m coils or cut to length |
Cross-Section & Conductor Reference
| Cross-section | AWG equiv. | Conductor type | Approx. OD (mm) | Max resistance (Ω/km at 20°C) |
|---|---|---|---|---|
| 0.5 mm² | 20 AWG | Stranded | 3.8 | 39.0 |
| 0.75 mm² | 18 AWG | Stranded | 4.2 | 26.0 |
| 1.0 mm² | 17 AWG | Stranded | 4.6 | 19.5 |
| 1.5 mm² | 15 AWG | Stranded | 5.0 | 13.3 |
| 2.5 mm² | 13 AWG | Stranded | 5.8 | 7.98 |
| 4.0 mm² | 11 AWG | Stranded | 6.5 | 4.95 |
| 6.0 mm² | 9 AWG | Stranded | 7.5 | 3.30 |
| 10 mm² | 7 AWG | Stranded | 9.0 | 1.91 |
| 16 mm² | 6 AWG | Stranded | 11.0 | 1.21 |
Key Features
Thermal performance
- 500°C continuous operating temperature
- Mica insulation retains electrical isolation above rated temperature
- No organic polymer — no off-gassing, no carbonisation at service temp
- Suitable for repeated thermal cycling without insulation degradation
- Performs in both oxidising and reducing furnace atmospheres
Conductor & mechanical
- Nickel-plated copper — oxidation resistant at high temperature
- Bare copper option for cost-sensitive applications
- Treated fiberglass braid — abrasion and mechanical protection
- Dimensionally stable — no shrinkage or deformation at service temperature
- Cut-to-length supply — minimises waste on short furnace wiring runs
- 500°C rated — highest temperature class in the GN series, suited for the most extreme furnace wiring environments
- Mica insulation will not burn — remains electrically intact even if the fiberglass braid outer covering is charred
- 500V AC voltage rating — sufficient for mains-voltage furnace heating element connections
- No smoke or toxic fumes — inorganic insulation produces no harmful combustion products at operating temperature
- Custom cross-sections and lengths — available from 0.5 mm² to 16 mm², cut to length from 1 m
Common Applications
Industrial furnaces & kilns
GN500 furnace wire is the standard specification for internal element lead wires, thermocouple connection leads, and control wiring inside continuous belt furnaces, batch box furnaces, ceramic kilns, and sintering furnaces where sustained temperatures between 400°C and 500°C make all silicone and PTFE-insulated alternatives unsuitable. The wire connects heating elements to their terminal blocks and runs through the furnace hot zone where no polymer-insulated wire can survive.
Glass and ceramic manufacturing
Used for electrode connection leads, pyrometer wiring, and temperature controller wiring inside glass annealing lehrs and ceramic decoration kilns, where ambient temperatures in the connection area regularly exceed 300°C and brief excursions above 400°C are common during firing cycles.
Metal heat treatment
Specified for internal wiring of vacuum heat treatment furnaces, atmosphere-controlled annealing furnaces, and salt bath furnaces where combination of high temperature, chemical atmosphere, and long continuous duty cycles demands the highest-rated wire available.
Semiconductor & electronics manufacturing
Used in diffusion furnaces, CVD reactors, and reflow oven internal wiring where process temperatures approach or exceed 400°C and contamination from wire decomposition products is unacceptable. The inorganic mica insulation produces no organic decomposition products that could contaminate the process atmosphere.
Other applications
- Infrared heating panel element connections
- Industrial baking and curing oven wiring
- Cremation and incineration equipment
- High-temperature laboratory furnace wiring
- Smelting and foundry equipment internal connections
GN Series Temperature Rating Comparison
| Designation | Max temperature | Insulation type | Typical application |
|---|---|---|---|
| Silicone rubber wire | 200°C | Extruded silicone rubber | Motor leads, appliance wiring |
| PTFE wire | 250°C | Extruded PTFE/FEP | Chemical equipment, lab instruments |
| GN300 / Mica-glass | 300°C | Mica + fiberglass braid | Furnace wiring, oven elements |
| GN450 / Mica-glass | 450°C | Mica tape + fiberglass braid | High-temperature kilns, furnaces |
| GN500 (this product) | 500°C | Heavy mica tape + treated braid | Extreme-temperature furnace wiring |
Installation Notes
GN500 furnace wire is not flexible and should not be installed in applications requiring repeated bending or dynamic flexing. It is designed for static internal wiring where the cable, once routed, remains in a fixed position throughout its service life. Minimum bend radius at installation is 10× the overall diameter; bending should be performed at room temperature before the wire enters the hot zone.
When terminating GN500 wire at ceramic terminal blocks inside the furnace, ensure the terminal clamp torque does not crush the mica insulation — use saddle clamps or ring terminal lug crimps where possible. Outside the furnace hot zone, standard PVC or silicone-insulated wire may be used for connections from the furnace terminal strip to the control panel.
Custom lengths from 1 m available. GN500 furnace wire is typically purchased in short lengths for maintenance replacement. Cut-to-length orders are accepted with no minimum order on standard cross-sections. Contact us for pricing and availability.
Why Choose CableApex
CableApex supplies GN500 high temperature furnace wire manufactured to GB/T 13033 specification with mica tape sourced from certified mineral suppliers and tested for dielectric strength at operating temperature. Our Yangzhou production facility has supplied mica-insulated wire to furnace manufacturers, kiln builders, and industrial equipment OEMs for over 15 years. All GN500 wire is supplied with conductor resistance test reports and insulation withstand test certificates on request.
