TFFN & THHN Wire

TFFN and THHN wire are go-to choices for safe, code-compliant electrical installations across residential, commercial, and industrial projects. TFFN (Thermoplastic Flexible Fixture Nylon) is commonly used as fixture wire inside lighting, control cabinets, and appliances where flexibility and tight bends matter. THHN (Thermoplastic High Heat-Resistant Nylon-coated) is a building wire for feeders and branch circuits pulled through conduit and raceways. Many THHN products are dual-rated THHN/THWN-2, expanding suitability to wet locations.

Both wire types feature a copper conductor, PVC insulation, and a tough nylon jacket that lowers pull friction and resists abrasion, oil, and gasoline. THHN is typically rated 600V and 90°C in dry locations; THWN-2 adds 90°C in wet environments. TFFN fixture wire is commonly rated 600V and 90°C dry and is intended for dry, protected spaces. Look for UL listed and NEC compliant markings to match specifications and inspection requirements.

Benefits you’ll notice on the job:
- Smooth pulls through conduit thanks to the nylon jacket
- Reliable heat performance at higher temperatures
- Strong chemical and abrasion resistance for long service life
- Broad color options for easy circuit identification
- Available in solid or stranded copper (TFFN is usually stranded for flexibility)

Selection tips to get it right the first time:
- Choose the correct gauge using ampacity charts and consider voltage drop on longer runs
- Verify location ratings: use THHN/THWN-2 for wet or damp areas; reserve TFFN for dry, protected spaces
- For outdoor conduit, select sunlight-resistant THHN/THWN-2
- Do not direct-bury THHN or TFFN unless specifically rated for it
- Match wire to the correct conduit type and fill limits for code compliance
- Check print legends for size, rating, and temperature class before purchasing

Whether you’re wiring panels, running conduit to equipment, or outfitting fixtures, TFFN wire and THHN wire offer dependable performance, easy handling, and clear compliance with modern electrical standards. Find common sizes from 14 AWG upward, sold by the foot or on spools, to keep projects on time and within spec.