| Standard — UL | UL 3074 (silicone rubber, 150°C, 600 V, AWM Style 3074); UL 3122 (silicone rubber, 200°C, 600 V, AWM Style 3122); UL 3257 (silicone rubber + fibreglass braid, 250°C, 600 V, AWM Style 3257); UL 3288 (mica/glass tape + fibreglass braid, 450°C, 600 V, AWM Style 3288); UL 1330 (FEP, 200°C, 600 V); UL 1332 (PTFE, 200°C, 600 V) |
| Standard — CSA | CSA C22.2 No. 127 (equipment wire); CSA AWM I A/B (recognized component, on request) |
| Standard — International | IEC 60227 / HD 21 (for PVC wires, not applicable to high-temperature wire — the thermal class of high-temperature wire exceeds the scope of PVC-based wiring standards); VDE 0250-502 (silicone, Germany) |
| Rated Voltage | 600 V AC (UL 3074/3122/3257/3288); also available at 300 V for thin-wall PTFE wire where space constraints require a lower voltage rating and a thinner insulation wall |
| Conductor Material — Bare Copper | IEC 60228 / ASTM B3; for continuous operating temperatures ≤150°C where copper oxidation over the wire's service life is acceptable |
| Conductor Material — Nickel-Plated Copper | Nickel plating 2–5 μm thickness per ASTM B355; for 150–250°C continuous; the nickel plating is the standard protection for elevated-temperature copper conductors — it prevents the copper from oxidizing to black CuO scale at these temperatures, maintaining low terminal contact resistance |
| Conductor Material — Silver-Plated Copper | Silver plating 1–3 μm thickness; for 150–200°C where the wire must be solderable (nickel-plated copper requires activated flux and higher soldering temperatures — silver-plated copper solders with standard Sn-Pb or Sn-Ag-Cu solder) |
| Conductor Material — Pure Nickel | Nickel 200 (99.6% Ni) per ASTM B160; for >250°C applications; pure nickel has higher resistivity (9.6 × 10⁻⁸ Ω·m at 20°C vs 1.68 × 10⁻⁸ for copper — approximately 5.7× higher) and a higher positive temperature coefficient of resistance; the conductor cross-section must be increased relative to copper to achieve the same circuit resistance and current rating — typically 2–3 AWG sizes larger |
| Conductor Class | IEC 60228 Class 5 flexible stranded (standard for equipment wiring); Class 2 stranded for heavier power leads; Class 1 solid for automated wire processing (PCB insertion, wire-wrap) |
| Conductor Cross-Sections — Metric | 0.22, 0.34, 0.50, 0.75, 1.0, 1.5, 2.5, 4, 6, 10, 16, 25, 35, 50 mm² |
| Conductor Sizes — AWG (UL) | AWG 24 (0.22 mm²), AWG 22 (0.34 mm²), AWG 20 (0.52 mm²), AWG 18 (0.82 mm²), AWG 16 (1.31 mm²), AWG 14 (2.08 mm²), AWG 12 (3.31 mm²), AWG 10 (5.26 mm²), AWG 8 (8.37 mm²), AWG 6 (13.3 mm²), AWG 4 (21.2 mm²), AWG 2 (33.6 mm²), AWG 1 (42.4 mm²), AWG 1/0 (53.5 mm²) |
| Insulation — Silicone (UL 3074) | Silicone rubber; rated 150°C; Shore A 60–80; 0.4–1.2 mm wall thickness per wire size and voltage per UL 62 |
| Insulation — Silicone (UL 3122) | High-temperature silicone rubber; rated 200°C; Shore A 60–80; enhanced thermal stabilizer for the higher temperature class |
| Insulation — Silicone + Fibreglass Braid (UL 3257) | Silicone rubber inner insulation + fibreglass braid outer covering saturated with high-temperature finish; rated 250°C; the fibreglass braid provides mechanical protection and prevents the silicone surface from sticking to hot surfaces |
| Insulation — Mica/Glass Tape + Fibreglass Braid (UL 3288) | Phlogopite mica paper on glass fibre carrier (0.08–0.12 mm) helically wrapped over the conductor with ≥25% overlap + fibreglass braid outer covering saturated with high-temperature inorganic binder (sodium silicate or silicone resin); rated 450°C; this is the highest-temperature flexible wire construction commercially available — the mica tape provides the primary electrical insulation and the fibreglass braid provides the mechanical structure; at 450°C, all organic materials (including the silicone binder in the fibreglass braid) have decomposed, but the mica and glass fibre remain intact as a continuous electrical insulation and mechanical covering |
| Insulation — PTFE (UL 1332) | Extruded or tape-wrapped polytetrafluoroethylene (PTFE); rated 200°C continuous, 260°C short-term; 0.25–0.76 mm wall; PTFE is semi-rigid — less flexible than silicone but offers the thinnest insulation wall for a given voltage class due to its higher dielectric strength (18–22 kV/mm) |
| Insulation — FEP (UL 1330) | Extruded fluorinated ethylene propylene (FEP); rated 200°C; 0.25–0.76 mm wall; FEP is melt-processable (unlike PTFE which must be extruded as a paste or tape-wrapped and sintered) and is available in thinner walls and more consistent extrusion than PTFE; FEP has slightly lower temperature rating (200°C vs 260°C short-term for PTFE) but is more economical |
| Insulation Colors | Solid: white, black, red, blue, yellow, green, brown, grey, orange, violet, natural (translucent silicone or amber PTFE/FEP); striped: any two-color combination with longitudinal stripes; the color is integral to the insulation compound — it does not rub off or fade at the rated operating temperature |
| Maximum DC Conductor Resistance at 20°C — Copper | Per IEC 60228 / ASTM B258 for the conductor class and cross-section; 89.2 Ω/km (AWG 24, 0.22 mm²) to 0.386 Ω/km (AWG 1/0, 53.5 mm²) |
| Maximum DC Conductor Resistance at 20°C — Nickel | Approximately 5.7× the copper value per the resistivity ratio (nickel resistivity 9.6 × 10⁻⁸ Ω·m / copper 1.68 × 10⁻⁸ Ω·m = 5.7×) |
| Insulation Resistance at 20°C — Silicone / PTFE | ≥200 MΩ·km (minimum at 500 V DC, 1 min); the IR of silicone and PTFE is significantly higher than PVC (≥10 MΩ·km) and is maintained better at elevated temperature |
| Test Voltage (AC — Spark Test, In-Line) | 100% spark test during manufacturing per UL 1581; test voltage depends on the rated voltage and insulation thickness — typically 3–10 kV AC; any pinhole or thin spot in the insulation is detected and the wire is cut out |
| Dielectric Withstand (AC — Finished Wire) | 2 500 V AC / 1 min (600 V rated wire, per UL 1581); the withstand test is applied to a sample of finished wire — the wire must not break down at the test voltage |
| Temperature — UL 3074 (Continuous) | 150°C conductor temperature |
| Temperature — UL 3122 (Continuous) | 200°C conductor temperature |
| Temperature — UL 3257 (Continuous) | 250°C conductor temperature |
| Temperature — UL 3288 (Continuous) | 450°C conductor temperature (at this temperature, all organic components of the wire have decomposed — the mica and fibreglass are the active insulation and mechanical structure; the nickel-plated copper conductor survives, but the nickel plating may diffuse into the copper at 450°C over extended time, leaving bare copper exposed to oxidation) |
| Temperature — PTFE (Continuous / Short-Term) | 200°C / 260°C; PTFE has the highest short-term temperature excursion tolerance of the fluoropolymer insulation family |
| Temperature — FEP (Continuous / Short-Term) | 200°C / 220°C; FEP's short-term rating is lower than PTFE |
| Temperature — Low-Temperature Flexibility (Silicone) | -60°C; the wire remains flexible and can be routed at cryogenic temperatures |
| Temperature — Low-Temperature Flexibility (PTFE) | -100°C; PTFE retains some flexibility to cryogenic temperatures |
| Minimum Bend Radius — Silicone Wire | 3× wire OD (fixed routing); 5× wire OD (handling and installation) |
| Minimum Bend Radius — PTFE/FEP Wire | 5× wire OD (fixed); 10× wire OD (handling — the stiffer PTFE/FEP requires larger bend radii than silicone) |
| Stripability — Silicone | The silicone insulation strips cleanly from the conductor, leaving minimal residue; mechanical or thermal (hot-blade) stripping can be used; the strip force is moderate — higher than PVC but manageable with standard wire stripping tools |
| Stripability — PTFE/FEP | PTFE and FEP are more difficult to strip than silicone; thermal stripping (hot blade or laser) is preferred to avoid conductor damage; mechanical stripping with precision blade dies can be used for production volumes |
| Solderability — Nickel-Plated Copper | Requires activated (RA or RMA) flux and higher soldering temperatures (370–400°C vs 300–350°C for bare copper); the nickel surface is not as easily wetted by solder as bare copper or silver-plated surfaces; for applications requiring soldered terminations, specify silver-plated conductor instead of nickel-plated |
| Solderability — Silver-Plated Copper | Excellent — solders with standard Sn-Pb or Sn-Ag-Cu solder at standard temperatures; the silver plating does not oxidize and is easily wetted by solder; the preferred conductor finish for high-temperature wire that will be soldered |
| Flame Retardant — Silicone | UL VW-1 (UL 1581 vertical flame test); silicone ignites with difficulty, burns with a low flame, self-extinguishes, and forms a non-conductive silica ash |
| Flame Retardant — PTFE/FEP | Inherently non-flammable — LOI (Limiting Oxygen Index) >95%; PTFE will not sustain combustion in any oxygen concentration; the UL VW-1 test is passed by definition for solid PTFE/FEP insulation |
| Halogen Content — Silicone | Zero; silicone is halogen-free (no chlorine, bromine, or fluorine) |
| Halogen Content — PTFE/FEP | High fluorine content (76% by weight for PTFE); PTFE/FEP are halogenated polymers — they emit HF (hydrogen fluoride) and other fluorinated gases when heated to decomposition (>400°C); this is a consideration for applications where the wire may be exposed to fire or extreme over-temperature and halogen emission must be avoided — specify silicone (halogen-free) for these applications |
| Certifications | UL recognized component (AWM, UL 3074/3122/3257/3288/1330/1332); CSA on request; CE; RoHS; VDE on request; ISO 9001 manufactured |
