Factory-Direct Supply of Certified Wires and Conductors for Diverse Industrial Applications
Copper THHN Wire 600V
Voltage: 600V, UL-83 Listed, NEC raceway & conduit rated
Conductor: Soft copper, ASTM B-3 solid (AWG 20-12) & B-8 Class B stranded (AWG 14-700 MCM)
Insulation: PVC inner (0.56-1.27mm) + Nylon jacket (0.10-0.30mm) — 3-layer THHN build
Temperature: THHN 90°C dry / THWN 75°C wet — dual rating per NEC 310.104(A)
Range: 31 sizes AWG 20-700 MCM, 5.5-3,370 kg/km, solid & stranded variants
Ampacity: NEC Table 310.16 per ≤3 conductors, 30°C ambient
Standard: ASTM B-3/B-8, UL-83, NEMA WC-5
Product Overview
Copper THHN Wire 600V is the definitive North American single-core building wire — the standard conductor for power and lighting circuits in industrial, commercial, and residential conduit and raceway installations per the National Electrical Code (NEC). Manufactured to ASTM B-3/B-8, UL-83, and NEMA WC-5, THHN wire features the three-layer construction that defines the product category: a soft temper bare copper conductor (solid for AWG 20-12, Class B concentric-lay stranded for AWG 14 and up to 700 MCM), a colour-coded PVC insulation layer providing the primary dielectric strength, and an extruded Nylon (polyamide) outer jacket providing mechanical toughness — abrasion, chemical, oil, and gasoline resistance. The 90°C dry-location rating combined with the Nylon jacket's pull-through durability makes THHN the only single-core building wire UL-listed for the full conduit fill and cable tray installation density permitted by the NEC — the invisible productivity advantage that has made THHN the default specification on every North American commercial construction project for over 60 years.
This AWG/MCM standard version covers 31 sizes from AWG 20 (0.52mm² solid) to 700 MCM (355mm² stranded), with every size carrying both THHN 90°C and THWN 75°C ampacity ratings for up to three current-carrying conductors in a raceway — the standard NEC Table 310.16 installation condition that governs 99% of THHN installations. The stranded conductor range begins at AWG 14 (7-strand) and extends through progressively larger stranding patterns — 7-strand for 14-10 AWG, 19-strand for 8AWG-4/0 AWG, 37-strand for 250-500 MCM, 61-strand for 600-700 MCM — as specified by ASTM B-8 Class B concentric lay. The separate jacket thickness column (0.10-0.30mm) enables precise conduit fill calculations — a critical NEC compliance requirement where the sum of conductor cross-sectional areas must not exceed 40% of the conduit internal cross-section for new work.
Outer Jacket — Forest green PVC+Nylon, glossy with vertical gradient shading, thin grey ring separates stripped section at right
Copper Conductor — 19-strand bundle in 1-6-12 concentric lay, reddish-tan metallic finish, horizontal strand lines visible on side profile
Stripped-End Cross-Section — 19 circular copper strand ends visible at rightmost tip, confirming Class B concentric stranding
Solid & Stranded Copper (ASTM B-3/B-8)
Solid: AWG 20-12. Stranded: AWG 14-700 MCM, Class B concentric lay (7-61 strand). Soft temper for maximum conductivity and ease of termination.
PVC + Nylon 3-Layer Build
Inner PVC insulation (0.56-1.27mm) + outer Nylon jacket (0.10-0.30mm). THHN 90°C dry / THWN 75°C wet. Gasoline, oil, acid, and abrasion resistant.
AWG/MCM Standard Sizes
Pure North American AWG: 20 AWG → 700 MCM. 31 sizes, 5.5-3,370 kg/km. Every size dual-rated with 90°C THHN + 75°C THWN ampacity.
Nylon Pull-Through Advantage
Nylon jacket's low coefficient of friction enables pulling multiple conductors through long conduit runs — the defining installation advantage over ordinary PVC wire.
NEC Table 310.16 Ampacity
90°C THHN + 75°C THWN ratings per ≤3 current-carrying conductors in raceway — the standard NEC installation condition that governs virtually all THHN circuits.
UL-83 + NEMA WC-5 Listed
UL Listed for full NEC compliance. NEMA standard ensures dimensional interchangeability with all North American THHN manufacturers.
Technical Characteristics
| Rated Voltage | 600V |
| THHN Rating | 90°C — dry locations only per NEC 310.104(A) |
| THWN Rating | 75°C — wet locations per NEC 310.104(A) |
| Conductor Material | Soft temper bare copper — ASTM B-3 solid, ASTM B-8 Class B concentric strand |
| Construction | 3-layer: copper core → PVC insulation → Nylon jacket |
| Flame Resistance | UL-83 VW-1 vertical flame test |
| Standard | UL-83, NEMA WC-5, ASTM B-3, ASTM B-8 |
Applicable Standards
| Standard | Scope |
|---|---|
| ASTM B-3 | Soft or annealed copper wire — material standard for solid THHN copper conductors up to AWG 12. |
| ASTM B-8 | Concentric-lay stranded copper conductors, Class B — material standard for all stranded THHN conductors from AWG 14 to 700 MCM. |
| UL-83 | Thermoplastic insulated wires and cables — the defining UL standard for THHN construction, testing, and listing. Required for NEC compliance in all North American jurisdictions. |
| NEMA WC-5 | Thermoplastic insulated wire — ensures dimensional and performance interchangeability across all manufacturers, enabling competitive bidding on NEC-compliant installations. |
Technical Specifications
Soft temper copper per ASTM B-3 (solid) and ASTM B-8 Class B (stranded). PVC+Nylon insulation per UL-83. Ampacity per NEC Table 310.16: not more than 3 current-carrying conductors in raceway, 30°C ambient. THWN = 75°C wet, THHN = 90°C dry. All sizes single core, 100m/500m/1000m spools.
| AWG/MCM | Stranding (No./mm) | Insul. PVC (mm) | Jacket (mm) | O.D. (mm) | Amp 75°C (A) | Amp 90°C (A) | Weight (kg/km) |
|---|---|---|---|---|---|---|---|
| Solid Conductor | |||||||
| 20 | 1/0.80 | 0.56 | 0.10 | 2.2 | — | — | 5.5 |
| 18 | 1/1.02 | 0.56 | 0.10 | 2.5 | — | 14 | 8.7 |
| 16 | 1/1.29 | 0.56 | 0.10 | 2.8 | — | 18 | 13.5 |
| 14 | 1/1.63 | 0.56 | 0.10 | 3.2 | 20 | 25 | 21 |
| 12 | 1/2.05 | 0.56 | 0.10 | 3.7 | 25 | 30 | 33 |
| 10 | 1/2.59 | 0.56 | 0.10 | 4.5 | 35 | 40 | 52 |
| Stranded Conductor — Class B Concentric Lay | |||||||
| 14 | 7/0.62 | 0.56 | 0.10 | 3.4 | 20 | 25 | 22 |
| 12 | 7/0.78 | 0.56 | 0.10 | 4.0 | 25 | 30 | 36 |
| 10 | 7/0.98 | 0.56 | 0.10 | 4.8 | 35 | 40 | 54 |
| 8 | 7/1.23 | 0.76 | 0.10 | 5.9 | 50 | 55 | 81 |
| 6 | 7/1.56 | 0.76 | 0.10 | 7.0 | 65 | 75 | 133 |
| 4 | 7/1.96 | 0.76 | 0.10 | 8.4 | 85 | 95 | 213 |
| 2 | 7/2.47 | 0.76 | 0.10 | 10.1 | 115 | 130 | 341 |
| 1 | 19/1.56 | 1.02 | 0.13 | 12.0 | 130 | 150 | 474 |
| 1/0 | 19/1.75 | 1.02 | 0.13 | 13.2 | 150 | 170 | 571 |
| 2/0 | 19/1.97 | 1.02 | 0.13 | 14.6 | 175 | 195 | 739 |
| 3/0 | 19/2.21 | 1.02 | 0.13 | 16.2 | 200 | 225 | 936 |
| 4/0 | 19/2.48 | 1.02 | 0.13 | 17.9 | 230 | 260 | 1,189 |
| 250 MCM | 37/2.30 | 1.27 | 0.18 | 20.3 | 255 | 290 | 1,447 |
| 300 MCM | 37/2.52 | 1.27 | 0.18 | 22.0 | 285 | 320 | 1,727 |
| 350 MCM | 37/2.72 | 1.27 | 0.18 | 23.7 | 310 | 350 | 2,013 |
| 400 MCM | 37/2.91 | 1.27 | 0.18 | 25.3 | 335 | 380 | 2,261 |
| 450 MCM | 37/3.09 | 1.27 | 0.20 | 26.8 | 362 | 409 | 2,537 |
| 500 MCM | 37/3.26 | 1.27 | 0.20 | 28.0 | 380 | 430 | 2,820 |
| 550 MCM | 61/2.66 | 1.27 | 0.23 | 29.9 | 419 | 475 | 3,100 |
| 600 MCM | 61/2.78 | 1.27 | 0.23 | 31.2 | 433 | 489 | 3,380 |
| 650 MCM | 61/2.89 | 1.27 | 0.25 | 32.2 | 459 | 521 | 3,665 |
| 700 MCM | 61/3.00 | 1.27 | 0.25 | 33.4 | 468 | 530 | 3,370* |
Packaging & Delivery
| Parameter | Standard |
|---|---|
| Package | 100m/500m/1000m per spool per AWG; export wooden case & pallet |
| Spool Marking | Manufacturer, THHN/THWN, 600V, AWG/MCM, length, weight, batch, UL/NEMA marks |
| Colour Options | NEC standard THHN colours: black, white, red, blue, green, yellow, brown, orange, grey, purple, pink |
| Conductor Marking | THHN/THWN designation, AWG size, voltage rating, UL mark printed on the Nylon jacket per UL-83 marking requirements |
| Delivery Condition | Factory-new, tested per UL-83 / NEMA WC-5, UL Listed, ASTM certified, test certificate on request |
Typical Applications
THHN wire is the standard single-core building wire in every North American commercial and industrial electrical installation:
Commercial Building Conduit
The default specification for all North American commercial construction — office towers, retail, and institutional buildings. Nylon jacket survives 90m+ conduit pulls with multiple conductors.
Industrial Machine Tool Wiring
Per NFPA 79. Oil and gasoline-resistant Nylon jacket survives machine tool interiors. 90°C rating handles elevated ambient temperatures near motors and process equipment.
Branch Circuit & Feeder Wiring
AWG 14-4/0 covers every branch circuit and feeder size in a commercial building — lighting panels, receptacle circuits, HVAC equipment, and elevator feeders.
Service Entrance (THWN)
THWN 75°C wet rating qualifies for outdoor service entrance conduit — the standard wire from utility meter to main distribution panel in residential and commercial services.
North American NEC Markets
UL-83 Listed for all US and Canadian jurisdictions. NEC Table 310.16 ampacity values printed on every specification — no code interpretation required.
Conduit Fill Optimisation
Separate PVC and Nylon thickness columns enable precise conduit fill calculations per NEC Chapter 9 — a compliance advantage over single-thickness building wire data sheets.
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Frequently Asked Questions
As a factory, we offer flexible MOQ depending on the cable type. For standard stock items, MOQ is low; for customized specifications, please contact our sales team for a detailed quote.
Yes, Qiangli cables are manufactured in compliance with international standards such as UL, CE, TUV, and VDE. We provide full test reports and certificates upon request.
Absolutely. We have a dedicated R&D team that can customize cable structure, material, color, and printing to meet your specific project needs.
For standard products, lead time is usually 7-15 days. For large-scale project orders or customized products, it typically ranges from 20 to 30 days.
Yes, we provide free samples for most standard cables. You only need to cover the international courier costs. Contact us to arrange your sample shipment.