G-10 is the most versatile all-around composite laminate. 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. NEMA grades G10 and FR4 Glass-Cloth Reinforced Epoxy naturally have a yellow-cream to light-green color. Epoxy resins are among the most versatile and widely used plastics in the electronics field, primarily because water absorption is practically zero, rendering it an outstanding insulator. Beyond its electrical insulating properties, epoxy resins exhibit superior adhesive properties and great dimensional stability—shrinkage is usually less than 1 percent. The main difference between NEMA Grades G10 and FR4 is that FR4 is a fire retardant grade of G10 with higher operating temperature and some improved mechanical strength at elevated temperature. Therefore, FR4 can be safely substituted where G10 is called for, while G10 can never be substituted where FR4 is called for.
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
Technical Data Sheet • Chemical Resistance Chart