About GPO-3|Glass-
polyester laminate. A thermoset laminate with good electrical insulation properties, arc resistance, and flame retardancy. Less expensive than
G-10/FR-4. Used for electrical switchgear, bus bar supports, and transformer components. Machines with carbide due to glass fiber abrasiveness. Creates fiberglass dust, so use extraction. Compare to G-10/FR-4 (stronger, better mechanical properties) and
Phenolic Grade XX (different base resin, similar applications).