UL 1331 FEP Lead Wire 16 AWG — 150°C at 600 Vac, First Wall Bracket of a Three-Bracket Style
UL 1331 in 16 AWG is a single-conductor appliance wiring material with extruded FEP insulation, rated 150°C maximum at 600 Vac with a horizontal flame rating. At 16 AWG the insulation falls in the style’s first bracket — 30 AWG through 10 AWG at 20 mils minimum average thickness, 18 mils minimum at any point. Understanding where that bracket ends matters more in this style than it first appears, because the bracket boundaries in UL 1331 do not align with those in the otherwise closely comparable UL 1330. CableApex supplies UL 1331 16 AWG as a UL Recognized Component — file on record.
The One-Gauge Difference That Catches Specifications Out
UL 1330 and UL 1331 share the same 30 AWG to 4/0 AWG conductor span, the same 600 Vac rating, the same three wall values of 20, 30 and 45 mils, and the same FEP insulation. They differ in temperature rating — 200°C against 150°C — and in one detail that is easy to miss: where the first bracket ends. In UL 1330 the first bracket covers 30 AWG through 10 AWG and the middle bracket begins at 9 AWG. In UL 1331 the first bracket also covers 30 AWG through 10 AWG, but the middle bracket begins at 8 AWG, leaving 9 AWG outside the ranges named in the style’s table.
For a 16 AWG conductor such as this one, the difference has no practical effect — both styles specify 20 mils minimum average, and a design can be moved between them on temperature grounds alone. The caution applies when a specification sits at or near 9 AWG: the wall thickness assumed from one style should not be carried across to the other without checking the table for the style actually being ordered. When an inquiry involves conductors in the 10 to 8 AWG region, state the style and gauge together so the applicable wall can be confirmed against the correct table before the order is placed.
Wall Bracket Boundaries: UL 1331 and UL 1330
| Bracket | UL 1331 (this page) | UL 1330 | Wall, min avg / min at any point |
|---|---|---|---|
| First | 30–10 AWG (16 AWG here) | 30–10 AWG | 20 mils / 18 mils |
| Middle | 8–2 AWG | 9–2 AWG | 30 mils / 27 mils |
| Heaviest | 1–4/0 AWG | 1–4/0 AWG | 45 mils / 40 mils |
UL 1331 16 AWG Specifications
| Item | Specification |
|---|---|
| UL Style | 1331 — single conductor with extruded insulation |
| Temperature Rating | 150°C maximum |
| Voltage Rating | 600 Vac |
| Conductor | 16 AWG, solid or stranded, or Litz cable conductor of R/C (OBMW2) magnet wire rated minimum 150°C (style range 30 AWG–4/0 AWG) |
| Insulation | Extruded FEP, 20 mils minimum average thickness, 18 mils minimum at any point |
| Optional Covering | Extruded FEP, 2 mils minimum thickness; or glass braid, 7 mils minimum thickness |
| Flame Rating | Horizontal flame; VW-1 vertical flame test available |
| Oil Rating | Optional — 60°C or 80°C oil resistant |
| Gasoline Resistance | Optional |
| UL Recognition | UL Recognized Component — file on record |
| Marking | Per UL Subject 758 marking requirements; Litz product additionally marked “Litz conductors are manufactured using solderable magnet wire” |
| Permitted Use | Internal wiring of appliances |
| RoHS / REACH | Documentation available on request |
16 AWG as a Lead Wire Gauge
Within the first bracket, 16 AWG sits at the heavier end — enough conductor cross-section for element and motor lead duty, while still carrying the same 20 mils wall as the fine signal gauges further down the bracket. That combination produces a lead wire with a comparatively slim finished diameter for its current capability, which is often the reason it is chosen over a heavier gauge with a thicker wall when the constraint is the space available at a terminal or through a bushing rather than the current itself. Solid construction suits short fixed leads formed before installation; stranded is the general choice for routed leads; Litz construction is available where the lead carries high-frequency current, though at 16 AWG that is less common than at the finer gauges.
Applications
Within its permitted use — internal wiring of appliances — UL 1331 16 AWG serves as a lead wire for element connections, motor leads and internal power runs at 600 Vac in zones reaching 150°C. Where the lead contacts hot metalwork or is handled during service, the optional glass braid covering adds abrasion protection; where a second fluoropolymer layer or a contrasting identification colour is wanted with minimal diameter increase, the 2 mils FEP covering applies. Optional oil resistance at 60°C or 80°C and optional gasoline resistance are available for leads exposed to lubricants or fuel. For applications outside internal appliance wiring, confirm application suitability before specifying.
Key Features
- First wall bracket at 16 AWG — 20 mils average, slim diameter for the gauge
- Bracket boundaries differ from UL 1330 — confirm wall by style near 9 AWG
- 150°C maximum at 600 Vac across a 30 AWG–4/0 AWG style range
- Solid, stranded or Litz cable conductor construction
- Covering options: FEP from 2 mils, or glass braid from 7 mils
- UL Recognized Component — file on record
Request a Quote
CableApex supplies UL 1331 16 AWG from 100 m per color and responds to B2B inquiries within 12 hours. Specify conductor construction (solid, stranded or Litz), colors, covering type and any oil or gasoline requirements through the form below.
Other UL 1331 sizes: 18 AWG · 20 AWG · UL 1330 FEP Wire (200°C / 600 Vac)
