Heat Resistant Wire – Selection Guide and Full Product Range
Heat resistant wire is a broad category covering any single-conductor electrical wire with insulation rated for continuous service above the 70°C limit of standard PVC wire. The correct choice of heat resistant wire depends primarily on the continuous ambient temperature at the installation point — not on the process temperature of the equipment itself, but on the temperature actually experienced by the wire at its routing location — combined with the voltage and AWG requirements of the circuit.
CableApex manufactures and supplies heat resistant wire across four principal insulation technologies — PVC (to 105°C), silicone rubber (to 200°C), PTFE fluoropolymer (to 260°C), and mica tape (to 450°C) — all produced under UL Follow-Up Service File No. E333030, providing certified wire for every heat resistant application from elevated-ambient panel wiring through to extreme-temperature furnace element connections.
Heat Resistant Wire Selection by Temperature
| Max ambient temp | Wire type | UL AWM style | Voltage | AWG range | Best for |
|---|---|---|---|---|---|
| Up to 105°C | PVC insulated (BVR / UL 1015) | 1015 | 600V AC | 30 AWG–2000 kcmil | Panel wiring, motor leads near standard motors |
| Up to 200°C | Silicone rubber (AGRP / UL 3135) | 3135 | 600V AC | 26 AWG–12 AWG | Appliance wiring, motor leads in Class H motors, oven connections |
| Up to 260°C | PTFE fluoropolymer (UL 1659) | 1659 | 600V AC | 26 AWG–4/0 AWG | Chemical equipment, laboratory instruments, aerospace |
| Up to 450°C | Mica tape glass fiber (UL 5107/5128) | 5107/5128 | 300–600V AC | 26 AWG–550 kcmil | Industrial furnaces, kilns, smelting equipment |
Reprinted from Product iQ with permission from UL Solutions. ©2026 UL LLC. File No. E333030, last updated 2025-12-01.
Insulation Type Comparison
| Property | PVC (105°C) | Silicone rubber (200°C) | PTFE (260°C) | Mica tape (450°C) |
|---|---|---|---|---|
| Flexibility | Good | Excellent | Good | Rigid — static only |
| Chemical resistance | Moderate | Good | Excellent | Good (inorganic) |
| Fire resistance | Limited | Self-extinguishing | Self-extinguishing | Non-combustible mineral |
| Ageing at high temp | Hardens rapidly above 70°C | No hardening over service life | No hardening | Dimensionally stable |
| Cost | Lowest | Medium | Medium-high | Highest |
| UL style | 1015 | 3135 | 1659 | 5107/5128 |
How to Select the Right Heat Resistant Wire
Step 1 — Determine the wire ambient temperature
Measure or estimate the temperature the wire will experience at its routing location — not the process temperature of the equipment. A wire routed through a 500°C furnace hot zone must be rated for 500°C. A wire entering the furnace at the gland point on the exterior shell (typically 150–180°C for a 500°C furnace) only needs a 200°C rating. Many applications use silicone rubber wire for the connection lead from the control panel to the equipment entry point, and mica tape wire only for the section inside the hot zone.
Step 2 — Determine voltage and AWG
Match the voltage rating of the wire to the circuit operating voltage, with at least 20% margin. Select AWG based on the required current-carrying capacity derated for the installation temperature — wire current capacity reduces significantly at elevated temperatures; always check the derating curve for the specific insulation type at the actual installation temperature.
Step 3 — Check the application environment
If the installation involves chemical exposure, specify PTFE rather than silicone rubber. If the wire must flex repeatedly in service, specify silicone rubber (not mica tape). If fire circuit integrity is required — the wire must maintain electrical continuity during a fire — specify mica tape construction regardless of the normal operating temperature.
Common Applications by Wire Type
- PVC (UL 1015, 105°C) — motor leads, panel wiring in heated enclosures, VFD output cables
- Silicone rubber (UL 3135, 200°C) — appliance element wiring, Class H motor leads, oven connection leads, heater control wiring
- PTFE (UL 1659, 260°C) — chemical plant instrument cable, laboratory analytical equipment, semiconductor process equipment wiring
- Mica tape (UL 5107/5128, 450°C) — industrial furnace and kiln internal wiring, smelting equipment, fire circuit integrity systems
Ordering Information
Select the appropriate heat resistant wire type from the selection guide above, then navigate to the specific product page for detailed specifications, AWG reference tables, and ordering information. If the correct wire type is unclear for your application, contact our technical team with the installation ambient temperature, voltage, current, and environment details — we will recommend the correct specification.
UL AWM compliance documentation available for all types. File No. E333030 covers UL 1015, 3135, 1659, 5107, and 5128. Contact us for technical advice and pricing within 24 hours.
Why Choose CableApex
CableApex manufactures heat resistant wire across the full temperature spectrum — from 105°C PVC to 450°C mica tape — under UL Follow-Up Service File No. E333030 at our Yangzhou production facility. All insulation types are produced on dedicated lines with 100% online spark testing and continuous dimensional monitoring. We supply to appliance OEMs, furnace manufacturers, chemical equipment builders, laboratory instrument manufacturers, and electrical distributors across more than 40 countries, with in-stock availability for common AWG sizes in silicone and PVC types and 10–15 working day lead times for mica tape and PTFE types.
