1/0 High Temp Wire, Type MG, 450ºC

MG wire stands for Mica-Glass. It is an extreme-temperature lead wire engineered to withstand continuous operating temperatures up to 450°C (842°F) and short-term thermal spikes up to 550°C (1022°F). The name describes its rugged construction: a flexible 27% nickel-coated copper conductor wrapped in high-dielectric Mica composite tapes, protected by a heavy-duty fiberglass braid jacket treated with a high-temperature finish.

• If you need MG extreme-temp wire near you, Wire America offers a comprehensive inventory available by the foot or in bulk spools. We ship directly from regional hubs across the country, ensuring most orders arrive within 2 to 4 business days, with expedited overnight shipping available at checkout for critical outages.

Yes, our MG (Mica-Glass) wire is fully UL Style 5359 rated. UL 5359 is the official Underwriters Laboratories standard for single-conductor appliance wiring material (AWM) certified for use up to 450°C (842°F) and 600 volts. This classification ensures the wire has passed strict thermal, electrical, and flame-propagation testing required for heavy-duty industrial heating equipment, commercial ovens, and furnace control systems.

The primary difference is the temperature limit and the insulation material. TGGT wire uses PTFE (Teflon) and tops out at 250°C. MG wire replaces the Teflon with Mica tape, which allows it to handle nearly double the heat (450°C continuous). If your application involves open heating elements, commercial kilns, or blast furnaces that exceed 250°C, MG wire can prevent the insulation from melting or off-gassing.

MG wire is rated for continuous operation at temperatures up to 450°C (842°F), with a non-UL maximum rating of up to 538°C in specific applications.

MG wire is a multi-layered composite designed for structural and electrical integrity at 450°C.

• The Core: Stranded, soft-drawn copper coated with 27% nickel, which prevents the oxidation and embrittlement that occurs in standard copper at high temperatures.
• The Insulation: Two layers of high-grade, fiberglass-reinforced mica tape. Unlike polymer-based insulators that melt, mica is a naturally occurring mineral that thrives in extreme heat, providing a robust dielectric barrier.
• The Protection: An outer braided fiberglass jacket treated with a high-temperature saturant, which guards the internal layers against mechanical abrasion and flame exposure in harsh industrial environments.

Because MG uses mica tapes and multiple layers of glass, it is less flexible than SRML or TGGT. It is intended for fixed wiring inside heavy equipment where extreme heat is the primary concern, rather than frequent movement.

Standard high-temp wires (like TGGT or SRML) use polymers that begin to degrade or "cook" once temperatures consistently stay above 250°C. MG wire utilizes a Mica-Glass composite insulation that is inherently heat-stable; the mica actually thrives in extreme heat. By choosing MG, you are moving away from insulation that slowly decomposes to a solution that is designed to withstand continuous 450°C operation.

MG wire is the standard for high-temperature equipment where ambient temperatures exceed 250°C. It is specifically designed for applications like industrial kilns, blast furnaces, glass-annealing lehrs, and high-heat processing equipment. If your application involves high radiant heat or direct furnace exposure, MG’s 450°C-rated mica-glass construction is the premier choice to prevent insulation breakdown and electrical shorts.

Choosing the right high-temperature wire depends on your maximum operating temperature and the level of flexibility required.

• Up to 200°C: SRML (Silicone Rubber) is usually the best choice for flexible power leads in moderate heat.
• Up to 250°C: TGGT (Teflon/Glass/Glass) is the industry standard for most commercial heaters and appliances.
• Up to 450°C: MG (Mica-Glass) is the required solution for extreme industrial environments like kilns, furnaces, and smelters.
  If your application is stationary and exceeds 250°C, MG wire provides the necessary thermal barrier and conductor protection that other materials simply cannot support.

Yes. We carry a comprehensive range of high-temperature wire, including SIS (125°C) SRML (200°C), TGGT (250°C), and MG (450°C). Each product page includes detailed engineering specs, such as strand counts and UL listings. To view our complete inventory or download full spec sheets for every size we carry, please visit our Full High-Temperature Wire Collection here.