G-10/FR-4 (Glass Epoxy)
Glass-fabric reinforced epoxy — the highest-strength insulator we stock, and a laminate rather than a plastic. In sheet and rod.
What G-10/FR-4 is
Glass fabric reinforced epoxy with superior electrical and mechanical properties.
G-10 or FR-4
They are the same glass-epoxy laminate with one difference that decides the specification: FR-4 is the flame-retardant grade, G-10 is not. If the part sits in an enclosure or an application with a flammability requirement, it is FR-4. Otherwise the two behave alike. Against the unreinforced plastics, glass epoxy is chosen when a part has to insulate and carry real load at the same time — it is far stiffer and stronger than any thermoplastic insulator, and unlike them it will not soften and flow as it warms.
Machining G-10/FR-4
This is the most abrasive material we machine. The glass reinforcement destroys tooling — carbide is the minimum and diamond-coated tooling earns its cost on production runs, and a tool that would run all day in acetal is finished in minutes. It cuts dry and produces a hard, fine dust rather than chips, so extraction is a requirement rather than good practice. Delamination and edge breakout at the laminate layers are the failure modes: back the material where the cutter exits, keep tooling sharp, and drill with the workpiece properly supported.
Need G-10/FR-4 parts machined to print?
Send us a drawing and we will quote it. Precision plastic machining in Linden, New Jersey since 1968.