What is MTW/TEW Wire?
MTW stands for Machine Tool Wire. TEW stands for Thermoplastic Equipment Wire. They are types of hook-up wire approved by the national electric code to be used in switchboards, appliances, electronic circuits, control cabinets, and the wiring of machine tools. Typically, TEW has a bare copper conductor and MTW wire has a tinned copper conductor. However, most TEW is double listed as MTW wire since they may be used in similar applications.
MTW and TEW Wire Construction
As stated above, the main difference between these two wires is their conductor. While the tinned conductor provides greater corrosion resistance, it can be affected by humid environments, making it more ideal for dry locations. Both types of wire feature Polyvinyl Chloride (PVC) insulation. The PVC insulation provides excellent resistance to heat, moisture, and oil. Both types of wire have a voltage rating of 600V and a maximum temperature of 105°C.
Both MTW and TEW wire are often dual-rated wires. This means that a wire may meet more than one industry standard. Common standards for MTW and TEW wire include UL AWM Styles UL 1028, UL 1283, UL 1284, and UL 1015. There are many specifications for each rating, including AWG size, insulation thickness, and voltage rating.
|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||600V||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|
Since many of these standards are similar, there is a lot of overlap. However, checking product specifications is always important since differences can be minuscule. For example, a wire that is 8 AWG could possibly be AWM approved for UL 1028, UL 1283, and UL 1284 ratings. However, a wire that is 2 AWG could only have UL 1283 or UL 1284 ratings. Similarly, a 6 AWG could meet UL 1028, UL 1283, and UL 1015 because it has an insulation thickness of 60 mils. However, a 4 AWG may not meet any except UL 1015 if it has an insulation thickness of 80 mils.
MTW and TEW wires often meet SAE 1127 Type SGT and BC5W2 ratings as well. For example, 6 AWG to 4/0 bare copper wires that meet UL 1284 also qualify as SAE 1127 Type SGT. Tinned versions of these sizes meet BC5W2 standards as well. Within the wire and cable industry, there are many common dual ratings. The chart below explains common dual ratings for MTW wire. You can learn more about dual ratings in general here.
|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|
Tinned: 6 AWG to 4/0 AWG | Bare: 6 AWG - 750 MCM
|SAE 1127||Bare: 6 AWG to 4/0 AWG|
Allied Wire and Cable offers MTW/TEW wire that meets UL Styles 1283, 1284, 1028, 1015, and 10519. You can also customize your wires with our wide selection of value-added services. Have more questions about MTW and TEW wire? Contact us today!