eGRAF® HITHERM™ HT-1205
eGRAF HITHERM HT-1205 is a flexible pure graphite thermal interface material with a typical thickness of 0.127 mm (0.005″) and through-plane / in-plane thermal conductivity of 10 / 150 W/m·K at 700 kPa. The material delivers thermal impedance of 0.59 K-cm²/W at 200 kPa and 0.30 K-cm²/W at 700 kPa across an operating temperature range of -40°C to +400°C. UL 94 V-0 flammability rated, RoHS compliant, halogen free, and lead free.
Key Properties
- Thermal Conductivity @ 700 kPa (Through-Plane • In-Plane): 10 • 150 W/m·K
- Thermal Impedance @ 200 kPa: 0.59 K-cm²/W
- Thermal Impedance @ 700 kPa: 0.30 K-cm²/W
- Hardness: 85 Shore A
- Operating Temperature: -40°C to +400°C
- Typical Thickness: 0.127 mm (0.005″) ± 10%
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- Specifications
- Applications
- General Info
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Thermal Properties
| Property | Value | Test Method |
| Typical Thermal Conductivity @ 700 kPa — Through-Plane | 10 W/m·K | ASTM D5470 Modified |
| Typical Thermal Conductivity @ 700 kPa — In-Plane | 150 W/m·K | Angstrom’s Method |
| Thermal Impedance @ 200 kPa | 0.59 K-cm²/W | ASTM D5470 Modified |
| Thermal Impedance @ 700 kPa | 0.30 K-cm²/W | ASTM D5470 Modified |
| Operating Temperature | -40°C to +400°C | — |
| Specific Heat @ 25°C | 0.71 J/g·°C | — |
| Coefficient of Thermal Expansion — In-Plane | -0.4 ppm/°C | — |
| Coefficient of Thermal Expansion — Through-Plane | 27.0 ppm/°C | — |
Physical Properties
| Property | Value | Test Method |
| Typical Thickness | 0.127 mm (0.005″) ± 10% | — |
| Hardness | 85 Shore A | — |
Electrical Properties
| Property | Value | Test Method |
| Electrical Resistivity — In-Plane | 60 µΩm | ASTM C6111.4 |
| Electrical Resistivity — Through-Thickness | 1230 µΩm | ASTM C6111.4 |
Flame & Fire Performance
| Property | Value | Test Method |
| Flammability Rating | 94V-0 | UL 94 |
Adhesive Coating Option — Adhesive “A”
| Property | Value | Test Method |
| Nominal Thickness | 0.008 mm / 0.0003″ | — |
| Operating Temperature | -40°C to +150°C | — |
| Thermal Impedance per Side @ 110 kPa | 0.16 cm²·°C/W | ASTM D5470 Modified |
| Adhesive Strength — Typical | 700 g/cm² | ASTM D3163 (lap shear on glass) |
| Adhesive Strength — Minimum | 450 g/cm² | ASTM D3163 (lap shear on glass) |
Compliance & Material Composition
| Property | Value | Test Method |
| RoHS Compliant | Yes | — |
| Halogen Free | Yes | — |
| Lead Free | Yes | — |
Compliance
- UL 94 — Compliant (V-0)
- RoHS — Compliant
- Halogen Free
- Lead Free
- Thermal interface between heat-generating components and heatsinks
- Die-cut thermal gap pads and pads for electronics assemblies
- Laminated thermal interface constructions with plastic or adhesive carriers
- Low contact resistance interfaces in high-temperature service (up to +400°C)
- Thin-bondline thermal management in space-constrained assemblies
Common industries: electronics, power electronics, telecommunications, and high-temperature thermal management.
eGRAF HITHERM HT-1205 is the 0.127 mm flexible pure graphite grade within the HITHERM HT-1200 pure graphite series, engineered for applications that require low thermal contact resistance and high thermal conductivity. The flexible graphite construction can be easily die-cut and laminated with a variety of plastics and adhesives to support diverse design and assembly requirements. HT-1205 is the thinnest standard grade in the pure graphite series, providing the lowest thermal impedance at a given contact pressure within the line.
Thermally, the material delivers through-plane conductivity of 10 W/m·K and in-plane conductivity of 150 W/m·K at 700 kPa, with thermal impedance of 0.59 K-cm²/W at 200 kPa and 0.30 K-cm²/W at 700 kPa across an operating temperature range of -40°C to +400°C. Mechanically, the material has a 85 Shore A hardness, with a coefficient of thermal expansion of -0.4 ppm/°C in-plane and 27.0 ppm/°C through-plane.
Electrical resistivity is 60 µΩm in-plane and 1230 µΩm through-thickness. Specific heat is 0.71 J/g·°C at 25°C. An optional Adhesive “A” coating is available at 0.008 mm nominal thickness, with an operating temperature of -40°C to +150°C, thermal impedance per side of 0.16 cm²·°C/W at 110 kPa, and adhesive strength of 700 g/cm² typical / 450 g/cm² minimum (lap shear on glass per ASTM D3163).
Compliant with UL 94 V-0 flammability, RoHS, halogen-free and lead-free requirements. Test methods include Angstrom’s Method (in-plane conductivity), ASTM D5470 Modified (through-plane conductivity and thermal impedance), ASTM C6111.4 (electrical resistivity), and ASTM D3163 (adhesive lap shear).
What differentiates HT-1205 from HT-1210, HT-1220, or the polymer-enhanced HT-2500 series?
HT-1205 is the 0.127 mm pure graphite grade — the thinnest in the HT-1200 series — which gives it the lowest thermal impedance at a given contact pressure within the pure graphite line (0.30 K-cm²/W at 700 kPa, versus 0.40 for HT-1210). The pure graphite construction also provides a much wider operating range (-40°C to +400°C) than the polymer-enhanced HT-2500 series (-25°C to +125°C), at the trade-off of lower through-plane conductivity (10 W/m·K vs 16 W/m·K). HT-1205 is halogen free, whereas the HT-2500 series is not.
Why does thermal conductivity matter in material selection?
The function of a thermal interface material is to move heat from a component to a heatsink with minimum temperature rise. Thermal conductivity sets the bulk heat transport, and thermal impedance — which also captures contact resistance — determines real-world performance at a given bondline and pressure. HT-1205 provides 10 W/m·K through-plane and 150 W/m·K in-plane at 700 kPa, with thermal impedance of 0.30 K-cm²/W at 700 kPa, supporting both vertical heat extraction and lateral spreading.
What is the operating temperature range for HT-1205?
The operating temperature range is -40°C to +400°C. With the optional Adhesive "A" coating, the assembled operating range is reduced to -40°C to +150°C.
Is HT-1205 suitable for flame-rated and RoHS-regulated environments?
Yes. HT-1205 is rated UL 94 V-0 for flammability and is RoHS compliant, halogen free, and lead free, making it suitable for consumer electronics, telecom, industrial, and other regulated assemblies.
How should HT-1205 be specified?
Specify grade (HT-1205), thickness (0.127 mm), adhesive option (with or without Adhesive "A" coating), part geometry (die-cut, kiss-cut, or sheet), compliance requirements (UL 94 V-0, RoHS, halogen free, lead free), dimensional tolerances, and finished format.
