Allied Encyclopedia: MTW/TEW Wire

What is MTW/TEW Wire?

MTW/TEW wire is UL rated Flexible Machine Tool Wire. MTW stands for Machine Tool Wire and TEW stands for Thermoplastic Equipment Wire. The UL ratings are UL 1028, UL 1283, UL 1284 and UL 1015.
MTW/TEW cable is used in machine tool applications. These include switchboards, appliances, electronic circuits, control cabinets and the wiring of machine tools. MTW wire passes the VW-1 flame test and is also moisture resistant. This article will examine two types of MTW/TEW wire which is available with either a tinned copper and bare copper conductor.

TEW / MTW Wire Construction
TEW/MTW wire is available with conductors that are tinned copper hook up wire or stranded bare copper hook up wire. It is used primarily in the wiring of machine tools and control cabinets, electronic circuits and switchboards. This wire is UL 1028, UL 1283, UL 1284 and UL 1015 rated. This wire features PVC (polyvinylchloride) insulation which makes it resistant to heat, moisture and oil. TEW cable is available with a variety of wall thicknesses, weights and sizes.

UL Ratings

MTW and TEW have dual UL ratings. This simply means that the wire meets more than one industry standard. The most common UL ratings for these wires are UL 1028, UL 1283, UL 1284 and UL 1015.

Wire Size Conductor Temperature Rating Voltage Rating Min. Average Thickness
UL 1028 22 AWG-6 AWG Solid or stranded

Tinned or bare copper

105°C 600V 22-8 AWG/ 45 mils

7-6 AWG/ 60 mils

UL 1283 8 AWG-1000 MCM Solid or stranded

Tinned or bare copper

105°C 600V 60 mils
UL 1284 8 AWG-2 AWG Solid or stranded

Tinned or bare copper

105°C 300V 80 mils
UL 1015 30 AWG – 2000 MCM Solid or Stranded 105°C 600 V 30-9 AWG/ 30 mils

8-7 AWG/ 45 mils

6-2 AWG/ 60 mils

1-4/0 AWG/ 80 mils

250-500 MCM/ 95 mils

550-1000 MCM/ 110 mils

110-2000 MCM/ 125 mils

There are several characteristics of the wire that influence the UL rating. With these specific styles, a wire that is 8 AWG could possibly be approved as UL 1028, UL 1283, or UL 1284 ratings. However, a wire that is 2 AWG could only have UL 1283 or UL 1284 ratings. Another characteristic that can determine which UL ratings a wire could be approved as is the minimum average insulation thickness. A wire that is 6 AWG would overlap UL 1028 (60 mils), UL 1283 (60 mils), and UL 1015 (60 mils), and could potentially be dual rated as all three styles. However a wire that is 4 AWG would not be able have both ratings because the insulation thicknesses are 60 mils vs 80 mils.These thicknesses are not the same for both styles.  MTW/TEW wire also can have other dual ratings such as SAE 1127, Type SGT rating which are controlled by other organizations such as NEMA or SAE. A UL 1284 wire with a bare copper conductor in sizes 6 AWG to 4/0 can be dual rated as SAE 1127, type SGT, since the requirements of both styles overlap. For more information on dual ratings, check out our Allied Encyclopedia article on this topic.

While the above paragraph gives a full overview of how dual ratings can work, within the wire and cable industry, there are some very common dual ratings.  The chart below covers the most common dual ratings according to industry standards for MTW wire.

Main UL Rating Size
UL 1015 10 AWG and smaller
UL 1028 8 AWG
UL 1283 6-2 AWG
UL 1284 1 AWG and larger
BC5W2 Tinned: 6 AWG -4/0

Bare: 6 AWG – 750 MCM

There is also the BC5W2 rating for wires sized 6 AWG- 4/0 tinned and 6 AWG – 750 MCM bare.

mtw wire, tew wire, mtw/tew wire

MTW/TEW Wire

MTW and TEW are available to be customized to your needs. Utilize our Value-Added Services to stripe, print or dye your machine tool wire. For more more information on UL 1028, UL 1283 and UL 1284 MTW/TEW Wire, visit our website or submit an RFQ today.

MTW vs THHN | Product Knockout

Product_KnockoutOur Product Knock-out series is a match-up between two similar products. In boxing terms, think same weight class, same caliber, and same level of experience and amount of exposure. The purpose of these posts are for you to see a side-by-side view of two similar products, and to be able to understand which one will be crowned champ for your specific purposes. Take your seats and prepare for battle, because the gloves are coming out.

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

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.

MTW vs THHN

MTW vs THHN

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.

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