G10/FR4 Glass Reinforced Epoxy

(Micarta) (High Pressure Laminates) G10/FR4 Glass Reinforced Epoxy - natural (yellowish to light green) Technical Data Sheet    Chemical Resistance Chart
The most versatile all-around laminate and composite, this grade is a continuous glass woven fabric base impregnated with an epoxy resin binder. It has extremely high mechanical strength, good dielectric loss properties, and good electric strength properties, both wet and dry.

The main difference between NEMA Grades G10 and FR4 is that FR4 is a fire retardant grade of G10. Therefore, FR4 can be safely substituted where G10 is called for, while G10 can never be substituted where FR4 is called for. (G10 certifies to Mil-I-24768/2 GEE; FR4 certifies to Mil--24768/27 GEE-F.) NEMA grades G11 and FR5 Glass-Cloth Reinforced Epoxy -- natural color is typically yellow green to amber. This grade is similar to G10/FR4 with the addition of a higher operating temperature and some improved mechanical strength at elevated temperatures
NEMA G-10 certs to MIL-I-24768/2 GEE, IPC 4101/20, IEC 60893-3 Type 2 EP GC 201
NEMA FR-4 certs to MIL-I-24768/27 GEE-F, IPC 4101/21, IEC 60893-3 Type 2 EP GC 202