Epoxy TC (Thermally conductive)
Additive grade
ASTM D1763 · GB GB/T 13657 · ISO 3673-1
Gap fillers and heat-sink potting where 1–3 W/m·K is needed while keeping electrical insulation.
Values for the TC 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 |
TCThis page 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 | — |
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 TC?
Epoxy TC is Epoxy in the TC grade — gap fillers and heat-sink potting where 1–3 W/m·K is needed while keeping electrical insulation. Epoxy TC has a tensile strength of 40 MPa (5.8 ksi), weaker than 56% of polymer grades. Elongation at break is 0.8% and the elastic modulus is 8 GPa (1.16 Msi). Epoxy TC has a density of 2.2 g/cm³ (0.0795 lb/in³), heavier than 100% of polymer grades. Its glass-transition temperature is 120°C (248 °F).
Advantages
- Conducts heat well — 1.5 W/m·K (0.867 BTU/hr·ft·°F), better than 100% of polymer grades
- Low, predictable mold shrinkage — 0.2%, better than 94% of polymer grades
- Stiff — 8 GPa (1.16 Msi), better than 91% of polymer grades
- Polishes to a fine finish — 75/100, better than 86% of polymer grades
- High service temperature — 150°C (302 °F), better than 79% of polymer grades
Limitations
- Heavy — 2.2 g/cm³ (0.0795 lb/in³), worse than 100% of polymer grades
- Limited ductility — 0.8%, worse than 98% of polymer grades
- Difficult to weld — 0/100, worse than 98% of polymer grades
- Limited formability — 5/100, worse than 95% of polymer grades
- Difficult to machine — 25/100, worse than 93% of polymer grades
Epoxy TC properties
Typical room-temperature values for Epoxy TC; 24 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 TC has a density of 2.2 g/cm³ (0.0795 lb/in³), heavier than 100% of polymer grades. Its glass-transition temperature is 120°C (248 °F).
Mechanical15
Epoxy TC has a tensile strength of 40 MPa (5.8 ksi), weaker than 56% of polymer grades. Elongation at break is 0.8% and the elastic modulus is 8 GPa (1.16 Msi).
Thermal10
Epoxy TC is rated for continuous service to 150°C (302 °F). It conducts heat at 1.5 W/m·K (0.867 BTU/hr·ft·°F), better than 100% of polymer grades. Thermal expansion is 30 µm/m·K (16.7 µin/in·°F).
Electrical7
Epoxy TC is an electrical insulator with a dielectric strength of 15 kV/mm (381 V/mil) and a resistivity of 1×10¹² 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 TC 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 TC's machinability is poor (25/100, worse than 93% 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 TC
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 TC — frequently asked
What is Epoxy TC used for?
Epoxy TC 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 TC?
Epoxy TC has a typical tensile strength of 40 MPa (5.8 ksi) — weaker than 56% of polymer grades. Strength varies by condition: see the 10 listed tempers.
Is Epoxy TC easy to machine?
Not especially — machinability is rated poor (25/100, worse than 93% 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 TC 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 TC?
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 TC 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 TC?
Epoxy TC is rated for continuous use to about 150°C (302 °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.