Epoxy GF30
Reinforced grade
ASTM D1763 · GB GB/T 13657 · ISO 3673-1
GF30 = 30 % short glass fiber reinforced epoxy molding compound
Choose for stiff, dimensionally stable molded parts (encapsulation, electrical housings) where CTE must be halved versus neat resin.
Values for the GF30 condition
Other Epoxy grades and fills
Epoxy is listed in 10 conditions; see the grade overview at Epoxy.
Compare all 10 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
Syntactic foam / microballoon-filled low-density grade | Buoyancy modules, core materials and lightweight tooling fills where compressive strength per density rules. | — | 20 | 1.2 | 80 Shore D |
ESD / electrically conductive | Conductive adhesives, EMI/grounding bondlines and static-dissipative tooling surfaces. | — | 30 | 0.5 | 90 Shore D |
Thermally conductive | Gap fillers and heat-sink potting where 1–3 W/m·K is needed while keeping electrical insulation. | — | 40 | 0.8 | 90 Shore D |
Toughened / impact-modified | Structural adhesives and crash-tolerant bondlines — 3–5× fracture toughness at the cost of Tg and modulus. | — | 45 | 9 | 78 Shore D |
Mineral / silica filled encapsulation grade | Silica-filled potting/encapsulation compound — low CTE and shrinkage for electronics, transformers and semiconductor molding. | — | 55 | 1 | — |
FR | Brominated or phosphorus/ATH flame-retarded formulation for electrical enclosures, busbar and rail applications. | — | 55 | 2 | 88 Shore D |
High-Tg novolac / anhydride cured heat-resistant grade | For tooling, aerospace prepreg and under-hood parts needing service to ~180–200 °C; more brittle and needs high-temperature post-cure. | — | 70 | 1.8 | — |
GF30This page 30 % short glass fiber reinforced epoxy molding compound | Choose for stiff, dimensionally stable molded parts (encapsulation, electrical housings) where CTE must be halved versus neat resin. | — | 110 | 1.5 | — |
FR-4 / G-10 | Pick for PCB substrates, insulating plates and machined electrical parts needing high flexural strength plus V-0 rating. | — | 310 | — | — |
Carbon fiber / epoxy composite | Use when epoxy acts as the matrix of a structural CFRP laminate — highest specific stiffness, near-zero axial CTE. | — | 1,800 | 1.4 | — |
What is Epoxy GF30?
Epoxy GF30 is Epoxy in the GF30 grade — choose for stiff, dimensionally stable molded parts (encapsulation, electrical housings) where CTE must be halved versus neat resin. Epoxy GF30 has a tensile strength of 110 MPa (16 ksi), stronger than 91% of polymer grades. Elongation at break is 1.5% and the elastic modulus is 11 GPa (1.6 Msi). Epoxy GF30 has a density of 1.75 g/cm³ (0.0632 lb/in³), heavier than 95% of polymer grades. Its glass-transition temperature is 120°C (248 °F).
Advantages
- Stiff — 11 GPa (1.6 Msi), better than 97% of polymer grades
- Conducts heat well — 0.45 W/m·K (0.26 BTU/hr·ft·°F), better than 97% of polymer grades
- Low, predictable mold shrinkage — 0.15%, better than 97% of polymer grades
- Polishes to a fine finish — 75/100, better than 86% of polymer grades
- High service temperature — 155°C (311 °F), better than 81% of polymer grades
Limitations
- Limited ductility — 1.5%, worse than 98% of polymer grades
- Difficult to weld — 0/100, worse than 98% of polymer grades
- Low fracture toughness — 0.6 MPa·√m (0.546 ksi·√in), worse than 96% of polymer grades
- Heavy — 1.75 g/cm³ (0.0632 lb/in³), worse than 95% of polymer grades
- Limited formability — 5/100, worse than 95% of polymer grades
Epoxy GF30 properties
Typical room-temperature values for Epoxy GF30; 15 are specific to this condition. Other listed values are Epoxy reference data and may not represent this condition. Bars are the position among polymer grades.
Physical6
Epoxy GF30 has a density of 1.75 g/cm³ (0.0632 lb/in³), heavier than 95% of polymer grades. Its glass-transition temperature is 120°C (248 °F).
Mechanical15
Epoxy GF30 has a tensile strength of 110 MPa (16 ksi), stronger than 91% of polymer grades. Elongation at break is 1.5% and the elastic modulus is 11 GPa (1.6 Msi).
Thermal10
Epoxy GF30 is rated for continuous service to 155°C (311 °F). It conducts heat at 0.45 W/m·K (0.26 BTU/hr·ft·°F), better than 97% of polymer grades. Thermal expansion is 25 µm/m·K (13.9 µin/in·°F).
Electrical7
Epoxy GF30 is an electrical insulator with a dielectric strength of 20 kV/mm (508 V/mil) and a resistivity of 1×10¹³ Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (82/100), better than 56% of polymer grades. UV resistance is poor.
Sustainability4
Producing a kilogram of Epoxy GF30 takes about 137 MJ of energy and emits 6.6 kg of CO₂ — more than 80% of polymer grades. Typical recycled content is 0%.
Manufacturability6
Epoxy GF30's machinability is fair (35/100, worse than 84% of polymer grades); weldability not recommended (0/100); formability not recommended (5/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Epoxy GF30
Is Epoxy easy to machine?
Machines cleanly with sharp carbide (PCD for filled/laminate grades) at high speed, light feed and no coolant heat build-up; filled and glass-cloth grades are highly abrasive and the dust requires extraction.
Can Epoxy be welded?
Thermoset — cannot be welded or re-melted; joints are made by secondary epoxy bonding with abraded, solvent-cleaned surfaces.
Can Epoxy be formed, bent or molded?
Processed by casting, potting, RTM/infusion, prepreg lay-up, filament winding or transfer/compression molding; degas the mix, respect pot life, and post-cure (typically 80–180 °C) to develop full Tg.
What surface finishes work on Epoxy?
Sands and polishes to a high gloss; accepts paint and primers readily after abrasion; needs UV-blocking topcoat or clearcoat for outdoor service because aromatic epoxies yellow and chalk.
Epoxy chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| bisphenol-A diglycidyl ether (DGEBA) resE-51/E-44 type; novolac or cycloaliphatic epoxies substitute in HT/clear grades | 45 – 75 | 60 |
| amine or anhydride hardenerpolyamine, polyamide, DDS/DDM or MTHPA anhydride; stoichiometry set by EEW | 8 – 40 | 25 |
| reactive diluent / flexibilizere.g. BGE, C12-14 glycidyl ether, CTBN | 0 – 15 | 5 |
| mineral or glass fillersilica, alumina, glass fiber/cloth depending on variant | 0 – 70 | 0 |
| accelerator / additivesimidazole, BDMA, defoamer, pigment, FR package | 0 – 3 | 1 |
Epoxy GF30 — frequently asked
What is Epoxy GF30 used for?
Epoxy GF30 is typically used for composite laminates, structural adhesives, potting/encapsulation and tooling and molds. In short: baseline composite matrix; strongest structural adhesive resin; wide filled-grade range.
What is the tensile strength of Epoxy GF30?
Epoxy GF30 has a typical tensile strength of 110 MPa (16 ksi) — stronger than 91% of polymer grades. Strength varies by condition: see the 10 listed tempers.
Is Epoxy GF30 easy to machine?
Not especially — machinability is rated fair (35/100, worse than 84% of polymer grades). Machines cleanly with sharp carbide (PCD for filled/laminate grades) at high speed, light feed and no coolant heat build-up; filled and glass-cloth grades are highly abrasive and the dust requires extraction.
Can Epoxy GF30 be welded?
Not readily — weldability is rated not recommended (0/100). Thermoset — cannot be welded or re-melted; joints are made by secondary epoxy bonding with abraded, solvent-cleaned surfaces.
What surface finishes work on Epoxy GF30?
Sands and polishes to a high gloss; accepts paint and primers readily after abrasion; needs UV-blocking topcoat or clearcoat for outdoor service because aromatic epoxies yellow and chalk.
Can Epoxy GF30 be formed, bent or molded?
Processed by casting, potting, RTM/infusion, prepreg lay-up, filament winding or transfer/compression molding; degas the mix, respect pot life, and post-cure (typically 80–180 °C) to develop full Tg.
What is the maximum service temperature of Epoxy GF30?
Epoxy GF30 is rated for continuous use to about 155°C (311 °F), and briefly to 180°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- Engineered Materials Handbook Vol. 2 — Engineering Plastics — ASM International (1988)
- Engineered Materials Handbook Vol. 1 — Composites — ASM International (1987)
- ASTM D1763 — Standard Specification for Epoxy Resins — ASTM (2019)
- GB/T 13657 — Bisphenol-A epoxy resin — SAC (2011)
- IEC 61249 / NEMA LI-1 (FR-4, G-10 laminates) — IEC / NEMA (2020)
- Araldite / Aradur casting and adhesive system datasheets — Huntsman Advanced Materials (2023)
- EPON / EPIKURE resin technical data — Hexion (Westlake Epoxy) (2022)
- CES EduPack polymer records — epoxy (thermoset) — Ansys Granta (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.