UL 5107 Mica Wire — 200°C 450°C 600V Mineral-Insulated High-Temperature Wire for Germany

Why Mineral Insulation Exists — When Polymer Wires Reach Their Limit

Until UL 5107, every Style on this catalog has used a polymer-based insulation: PVC, XLPE, silicone rubber, PTFE, FEP, PFA. These materials cover the temperature range from 80°C up to 250°C — sufficient for the vast majority of industrial wiring applications. UL 5107 belongs to a different category entirely: mineral-insulated wire, where the primary dielectric is a layer of mica tape rather than any polymer.

German engineers searching UL 5107 Mica Hochtemperatur Draht Deutschland are working in applications where polymer insulation cannot survive — sustained operating temperatures above 250°C, where even PTFE (the highest-temperature polymer wire at 250°C) approaches its working limit. UL 5107 carries a dual rating of 200°C OR 450°C, with the 450°C rating placing it in a temperature class that has only one alternative class above it: ceramic-insulated thermocouple wires used in furnace interiors.

The reason mica works at these temperatures while polymers do not is structural. Mica is a naturally occurring sheet silicate mineral — chemically a complex aluminum potassium silicate — with a layered crystalline structure. Each layer is a thin, mechanically flexible sheet. The mineral structure is thermally stable to over 1000°C before the chemical bonds begin to break down. At 450°C, mica retains essentially all of its dielectric and mechanical properties unchanged from room temperature.

The Temperature Coordinate System — Where 450°C Lives

To put 450°C in working context, here is where common materials and processes sit on the continuous-service temperature scale:

• 105°C — Standard PVC hook-up wire (UL 1015) upper limit
• 125°C — XLPE thermoset wire (UL 3266, UL 3271) upper limit
• 200°C — Silicone rubber wire (UL 3071), FEP fluoropolymer (UL 1332) upper limit
• 250°C — PTFE (UL 1659), PFA (UL 10362) — the highest-temperature polymer wires
• 300°C — Soldering iron tip temperature, lead-free solder reflow oven peak
• 425°C — Industrial paint baking oven typical operating temperature
• 450°C — UL 5107 mica wire upper rating — gas turbine combustor exterior surfaces
• 500-700°C — Steam boiler outer surfaces, glass annealing furnace interior
• 800-1000°C — Glass tempering furnace interior, ceramic firing kiln
• 1000°C+ — Mica chemical decomposition limit / ceramic wire territory

UL 5107 sits at the upper end of practical industrial high-temperature wiring — applications where the wire must survive sustained exposure to temperatures that would destroy any polymer-based insulation within minutes.

Typical UL 5107 Applications in German Industrial Equipment

Industrial Oven and Drying Equipment Internal Wiring

German industrial oven manufacturers producing baking ovens, drying ovens, paint curing ovens, and powder coating cure ovens for North American distribution use UL 5107 for the wiring that runs inside or near the oven heated chamber. Internal connections to heating element terminals, thermocouple extensions inside the oven cavity, and control circuits routed through the oven housing all operate in temperatures that exceed polymer wire ratings.

Glass and Ceramic Production Equipment

German manufacturers of glass tempering equipment, ceramic kilns, and optical glass production equipment for export to North American specialty manufacturers use UL 5107 for sensor leads, control wiring, and instrumentation extensions inside or adjacent to the heated production zones. The 450°C rating provides margin even for equipment sections in close proximity to the production heat.

Industrial Heat Treatment Furnace Equipment

German heat treatment furnace manufacturers producing equipment for metallurgical processing — annealing furnaces, tempering furnaces, brazing furnaces — use UL 5107 for exterior chassis wiring and instrumentation routing where the equipment outer surfaces operate at sustained elevated temperatures.

Gas Turbine and Power Generation Auxiliary Wiring

German power generation equipment OEMs producing gas turbine peripherals, exhaust system instrumentation, and combustion monitoring equipment use UL 5107 for sensor leads and control wiring routed through high-temperature zones where standard fluoropolymer wires would be marginal.

UL 5107 Specifications

Engineering Notes from CableApex

Three points German engineers should know when first specifying UL 5107 mica wire:

1. “Why does UL listing require UL to determine current-carrying capacity for each application?” Polymer-insulated wires have well-defined ampacity curves based on insulation temperature class and ambient conditions — engineers can use NEC Table 310.16 or similar references to size conductors. Mica-insulated wires behave differently: the mica tape construction with glass braid covering creates a thermal envelope that depends heavily on the application’s specific cable bundling, free-air vs conduit installation, and adjacent heat sources. UL Subject 758 requires that for each specific UL 5107 application, the actual current-carrying capacity be evaluated by UL during the end-product certification process. This is not a defect of UL 5107 — it reflects that mica wire applications are typically very specific high-temperature situations that require individual engineering evaluation.
2. “Mica wire cannot be repeatedly flexed — what does this mean in practice?” Mica tape is a layered mineral structure that maintains dielectric integrity in static or one-time-bent installations, but loses dielectric strength when subjected to repeated flexing cycles. The mica layers can develop microscopic delamination points after thousands of flex cycles. This is why UL 5107’s listing language specifies “where not subjected to repeated flexing.” For routing inside an oven housing where the wire is installed once and remains static, this is not a constraint. For applications where the wire must move during equipment operation (door cables, articulating arm wiring), mica wire is the wrong choice — silicone rubber wires (UL 3071) provide elastomeric flexibility for flex applications even though they have lower temperature rating.
3. “What’s the difference between UL 5107 at 200°C rating vs 450°C rating?” Both ratings refer to the same wire construction — the difference is the silicone varnish or TFE finish applied to the glass braid covering. The 200°C rating uses silicone varnish-treated braid, which is more flexible and lower cost but degrades above 200°C. The 450°C rating uses TFE-finished braid, which costs more but maintains dielectric integrity at the higher temperature. The mica tape itself supports both temperature classes. Specify the 200°C variant when the actual operating temperature stays below 200°C continuous and you want lower cost; specify the 450°C variant when application temperatures exceed 200°C, with the additional cost justified by the temperature margin.

MOQ, Packaging & Shipping

MOQ varies by AWG, color combination, optional construction (assembly type, shield, covering), temperature class (200°C or 450°C), and production schedule — contact us for current MOQ on UL 5107. Mica wire production has more complex setup than polymer wire production — MOQs are typically higher than commodity AWM Styles. Standard packaging: spools or reels per customer specification. Export documentation: Commercial Invoice, Packing List, Certificate of Origin (CCPIT), Bill of Lading, UL Recognition reference letter (File No. E333030), RoHS Declaration, REACH SVHC Declaration, MSDS. HS Code: 8544.49. CIF Hamburg or Rotterdam, transit time 25–30 days from Shanghai or Ningbo origin port.

Related UL Styles for Extreme High-Temperature Applications

UL 5107 buyers commonly cross-reference: UL 5128 (450°C / 300V mica + glass braid, 24-4 AWG — lower-voltage mica wire alternative), UL 5334 (450°C / 300V single-conductor mica + glass braid, 24-4 AWG — different mica composite construction), UL 5335 (450°C / 600V mica + glass braid, 22-4/0 AWG — same temperature/voltage class with different construction), and UL 1659 (250°C / 600V PTFE, 26-4/0 AWG — fluoropolymer alternative when 250°C is sufficient).

Please enable JavaScript in your browser to complete this form.

Company Name

Phone Email Work

Full Name *

Work Email *

Phone / WhatsApp

Request a Quote