When it comes to thermoset composites, few materials have held as much promise—and delivered as much—under extreme conditions as G30, a glass-reinforced polyimide laminate. Known for its exceptional thermal endurance and mechanical integrity, G30 has been a key player in critical applications where failure is not an option. Now, with the official NEMA reclassification of G30 to G15, this high-performance material is gaining greater clarity and standardization within the industry.

What is G30?

G30 is a thermoset composite consisting of woven glass cloth impregnated with polyimide resin. It was developed to meet the growing demand for high-heat and high-dielectric-strength applications in aerospace, electronics, and military sectors. What made G30 so unique was its ability to:

• Operate continuously at temperatures above 500°F (260°C)
• Resist thermal degradation
• Maintain dimensional stability in harsh environments
• Exhibit excellent dielectric loss properties at elevated temperatures

Unlike other glass-reinforced laminates (such as G10 or G11), G30’s polyimide resin system does not rely on halogenated compounds, making it more environmentally robust and fire-resistant, with extremely low outgassing—a key attribute in aerospace and vacuum environments.

The Shift to NEMA G15

Historically, G30 was widely recognized and specified in industry, but it never had an official NEMA designation, which often led to confusion or inconsistency in material call-outs and specifications. Recognizing this gap, NEMA (National Electrical Manufacturers Association) introduced G15 as the formal classification for glass/polyimide thermoset laminate materials.

Why the Change Matters:

• Standardization: With G15 as a recognized NEMA grade, manufacturers, designers, and specifiers now have a clear benchmark for performance and material characteristics.
• Compliance and Certification: G15 enables better alignment with military, aerospace, and IEC standards for materials.
• Procurement and Quality Control: Clear designation helps reduce errors in sourcing and inspection, making supply chains more efficient.

Applications of G15 (Formerly G30)

G15 continues the legacy of G30 in advanced industries where performance is mission-critical:

• Aerospace Systems: For structural components, insulators, and support brackets that must endure high temperatures and outgassing limits.
• Military Electronics: In radar systems, avionics, and missile components that operate in extreme thermal and dynamic environments.
• Semiconductor Manufacturing: As insulating and structural materials inside vacuum chambers and plasma environments.
• High-Temperature Electrical Insulation: For motors, transformers, and devices requiring continuous operation in elevated heat.

Looking Ahead

As demands on materials increase, especially in defense, space exploration, and high-temperature electronics, G15 provides an essential solution. Its reclassification is more than a name change—it's a signal to engineers, designers, and specifiers that this material is a recognized cornerstone of reliable, high-temperature composite technology.

At Franklin Fibre, we’ve worked with G30/G15 for decades, supplying precision-machined components and raw material solutions to customers with the most exacting standards. If your application requires thermal resilience, dielectric integrity, and mechanical strength in extreme environments, G15 is the modern-day gold standard.