← Allied Encyclopedia: UL3239 and UL10475 UL1061 vs UL1007 | Product Knockout →

MTW vs THHN | Product Knockout

Tuesday, July 26, 2016

Product_KnockoutIn this addition of our Product Knockout, presented by Allied Wire & Cable, we will be seeing who is the better wire. Will it be MTW wire? or will it be THHN wire? While these parts have a few similarities, their differences are what truly set them apart. Our side-by-side comparison will help you decide which part is most applicable for you and your wiring needs. Now, grab a seat because these two wires are about to go head to head!

MTW wire and THHN wire are electrical PVC wires used in building applications. MTW and THHN are built in accordance with the National Electrical Code for general purpose wiring for installation in conduit or other recognized raceway. These cables share several overlapping characteristics, although there are a few distinct differences that set them apart.

What is MTW wire?

MTW wire stands for Machine Tool Wire, and as the name implies, its primary uses are related to the wiring of machine tools, appliances, and control cabinets. MTW wire is PVC hookup wire, and features either a stranded bare or tinned copper conductor and is known for being durable and flexible. This wire is resistant to heat, moisture, oil, and gasoline, and is rated for up to 600V and for use from -25°C to 90°C. MTW wire passes the VW-1 Flame Test and meets several UL ratings.

What is THHN wire?

THHN wire stands for Thermoplastic High Heat-resistant Nylon, and as we can tell from the name, this wire is made of thermoplastic material (PVC insulation), can withstand high temperatures, and features a nylon jacket. THHN wire is primarily used to carry electrical currents to external power sources. This wire is rated for up to 600V and up to 90°C in dry locations, and 75°C in wet locations. THHN wire features either a bare copper or aluminum conductor and comes in both stranded or solid, depending on the size.


MTW vs THHN Specs for Construction
  MTW Wire THHN Wire
Conductor Size 22 AWG-1000 MCM 14 AWG-1000 MCM
Conductor Type Stranded Solid or Stranded
Conductor Material Bare or Tinned Copper Bare Copper or Aluminum
Insulation Material Polyvinylchloride (PVC) Polyvinylchloride (PVC) with Nylon Jacket
Max. Temperature 90°C 90°C
Max. Voltage 600V 600V

Although both MTW wire and THHN wire are well suited for use in similar applications, there are a few characteristics that set them apart and can make a big difference when trying to decide which type of cable will best meet your needs. MTW and THHN can both feature a bare copper conductor, however THHN is available with an aluminum conductor, depending on size. THHN wire is less flexible than MTW wire for two reasons. At the core MTW offers a higher strand count in the conductor, making it more flexible than THHN, which also features a nylon coating that further restricts movement.


Winner by unanimous vote? Instead, it seems as if the match has ended in a technical decision. In this case it looks like our crowned champ depends on your specific application use. If you’re unsure if THHN or MTW would work best for your wire and cable needs, let Allied help you out! Compare full THHN and MTW specs or give your sales rep a call at 800-472-5655 with any questions.

Please login or register to post comments.