G10 FR4 (Mil-I-24768/27) is a laminated epoxy resin with a substrate of woven fiberglass formed under heat and pressure. Typically yellow to light green in color and available as sheets, tubes and rods, it is the fire-retardant version of G10, and has largely replaced G10 in most applications. If you’re traveling by air, you’re likely within a few feet of something made out of G10 FR4.

Its dielectric constant of 400-500 Volts per mil depending on thickness, and insulation resistance of 200,000 Megohms makes it an excellent choice of material for many advanced electronics, especially in the aviation industry. It is almost impervious to water absorption (0.1% to 0.25% absorption after 24 hours), even in environments with high moisture content.

As well, the material is nearly immune to shrinkage, holding its form factor and dimensional stability at temperatures as high as 285° F. This property makes it ideal for use in electronic equipment with components that generate excessive heat. Should it combust at higher temperatures, the bromine added during the manufacturing process renders it self-extinguishing, another important factor for making its use in aerospace engineering so prominent.

Aerospace and Aviation use of G10 FR4

Its electrical insulating characteristics and its heat- and water-resistant properties finds the material in wide use in electrical and electronic applications. It has become the standard for the manufacture of copper-clad printed circuit boards. Other electrical components—including arc shields, bus bars, insulators, lighting fixtures, terminal strips, timers, standoffs, switches, relays and transformers—often use it. It also serves as mechanical, heat or electrical insulators within electric generators, motors, switch boards and other devices.

With all of the modern circuitry and electronic components in use in today’s aircraft and in rocketry it makes sense that a durable and fire-retardent material such as G10 is such a go-to resource. As these systems and their construction become more compact and more sophisticated, the difficulty in properly machining or drilling holes to match engineering specifications becomes all the more daunting. JMJ Profile continues to create custom solutions for these needs, that pushes this technology further. JMJ has created many proprietary techniques for working with the material, as it can be very tricky to master.

G10 FR4 makes an ideal material to use for aviation and aerospace applications. SpaceX, a company that’s in the news regularly, uses it as a standard material in construction of their rocket systems. Likewise, Apache Helicopters have two sets of flight instrumentation—one for the gunner who sits up front and another for the pilot who sits in the rear section. The backs of both instrumentation panels use G10 FR4. Lockheed Martin uses both carbon fiber and G10 FR4 in manufacturing combat drones.


JMJ Profile, Inc has worked with major aerospace firms and contributed to the Aegis Missile Defense system. With more than 20 years delivering CNC, drilling and custom machining services using G10 FR4, we invite you to contact us or submit an RFQ.

Also see: Mil-I-24768/27

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