TW/THW is a solid or stranded, soft annealed copper conductor insulated with Polyvinylchloride (PVC). It is UL rated for 600 volts. #10, 12, and 14 AWG are 19 strands, all others are “highly flexible” stranding constructions.

Canadian Standards Association (CSA) listed AWM-IA (Class I Group A) and TEW products are 600 V FT-1 rated. All our standard products are compliant and multi-listed as types TW, THW, MTW, TEW, and the applicable AWM Style Number.


TW/THW is most often used in general purpose wiring circuits, for machine tool wiring and the internal wiring of appliances. Common applications include control panels, wiring for refrigeration equipment, air-conditioning equipment, control wiring of machine tools, automatic washers, etc. It can be used in dry locations up to 90°C (ampacity is limited to 75°C conductor temperature per NFPA 79); or wet locations or other applicable locations when exposed to oil or coolant at temperatures up to 60°C. CSA Type TEW rating permits use in dry locations up to 105°C; or wet locations or other applicable locations when exposed to oil or coolant at temperatures up to 60°C. Our standard circuit size (#10, 12, 14 awg) products are marked Style 1015.

Solid TW/THW is also commonly used in general purpose grounding, such as CATV installations, swimming pool pumps and lighting, telephone and communications, and traffic light signals. Protection from shock or shorts is the key.

The governing standard for application of these products is the National Fire Protection Association (NFPA) Publication #79.


Our TW/THW is produced to the following specifications and requirements:

  • UL
  • CSA
  • NFPA #79
  • Caltrans

TW/THW Spec Sheet

Available Products

  • Sizes #22 through 1/0 AWG
  • Solid or Stranded
  • Up to 12 Color Options
  • Standard insulation is a soft, flexible PVC

Custom Options

  • Tinned wire available for all sizes
  • Striping or Twisting available
  • Custom lengths and packaging
  • VW-1 available upon request
  • Highly Flexible Class Stranding


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