G7 is a laminate sheet made from high-performance silicone resin and a woven fiberglass substrate, qualifying for NEMA G-7 and MIL-I-24768/17 standards. It is a flame-resistant material featuring a low dissipation factor with high heat and superior arc resistance. Glass silicone materials like G7 work well in wet or dry conditions and are ideal for applications requiring solid mechanical and electrical properties.

G7 Composition and Material Properties

Although glass silicones do not maintain strength properties as well as phenolics and epoxies in normal conditions, they offer better strength in higher temperatures, up to 200 degrees Celsius. In addition, it has low-smoke evolution while meeting the needs of Class H insulation. G7 differs from typical glass phenolic sheets because its resin is silicone-based.

G7 glass silicone’s primary material properties include the following:

• Specific gravity: 1.78
• Tensile strength: 45,000 pounds per square inch (psi)
• Flexural strength – LW -A 0.125″: 25,000 psi
• Shear strength: 17,000 psi
• Bond strength: 900 psi
• Hardness (Mohs Scale): 105
• Flammability rating: 94V-0
• Maximum operating temperature: 220 degrees Celsius (428 degrees Fahrenheit)
• Izod impact strength at 49 degrees Celsius -LW: 6.50
• Water absorption over 24 hours: 0.20
• Coefficient of thermal expansion in degrees Celsius (x10^-5): 1.00

G7 Materials We Offer

At Atlas Fibre, we stock a comprehensive range of G7 silicone shapes and sizes at our various locations, including:

• Sheets: If your operation performs in-house machining in fabrication, Atlas Fibre can supply you with the required sheets. We offer sheets in various thicknesses and sizes, including sheets cut to size for your unique project requirements.
• Tubes: We offer an extensive range of G7 tubes to meet the needs of various applications, from small-diameter tubing for welding tips to heavy-walled tubing for intense heat projects.
• Rods: We supply G7 glass silicone rods in multiple diameters and thicknesses to meet your application’s needs. Although the typical stock length is 48 inches, we offer custom lengths up to 120 inches for special projects.

G7 Uses and Applications

G7 glass silicone’s primary benefits include superior arc and heat resistance properties. Because of its exceptional electrical resistance and high stability in elevated temperatures, G7 is perfect for constructing tips inside welding guns. G7 laminate is also self-extinguishing and stable in high humidity, making it ideal for the following applications:

• Arc barriers and plates
• Insulation
• Heating systems
• Appliances
• Terminal boards
• Spacers, sleeves, and wedges
• Telecom equipment
• Transformers

Discover More With Atlas Fibre

If you want to learn more about G7 laminate material and how it can benefit your unique application, the experts at Atlas Fibre can assist you. Our team can evaluate your project requirements and recommend the materials to deliver the highest performance. Our extensive inventory enables us to offer some of the industry’s fastest turnaround times.

We have decades of experience supplying and machining thermoset composites, including stock shapes for glass silicone sheets like G7. Call 847-565-1996 or contact us online today to request a quote or additional technical information.

*Atlas Fibre LLC provides this data as information only and does not imply any warranty for its use or application. Test results for a specific sheet or lot are available for a fee upon request.