eGRAF® HITHERM™ HT-1220
eGRAF HITHERM HT-1220 is a flexible pure graphite thermal interface material with a typical thickness of 0.51 mm (0.020″) and through-plane / in-plane thermal conductivity of 10 / 150 W/m·K at 700 kPa. The material is the thickest grade in the HITHERM HT-1200 pure graphite series, operating across a 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
- Hardness: 85 Shore A
- Operating Temperature: -40°C to +400°C
- Typical Thickness: 0.51 mm (0.020″) ± 5%
- Electrical Resistivity (In-Plane • Through-Thickness): 60 • 1230 µΩm
- Flammability: UL 94 V-0
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- Specifications
- Applications
- General Info
- FAQs
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 |
| 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 | 0.51 mm (0.020″) ± 5% | — |
| 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
| Property | Value | Test Method |
| Adhesive “A” Coating Availability | Not available on HT-1220 grade | — |
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 for electronics assemblies
- Laminated thermal interface constructions with plastic carriers
- Low contact resistance interfaces in high-temperature service (up to +400°C)
- Thicker bondline thermal management where additional graphite bulk is required
Common industries: electronics, power electronics, telecommunications, and high-temperature thermal management.
eGRAF HITHERM HT-1220 is the 0.51 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 to support diverse design and assembly requirements. HT-1220 is the thickest standard grade in the pure graphite series, providing additional bulk for assemblies that need to bridge larger bondline gaps than the HT-1205 or HT-1210.
Thermally, the material delivers through-plane conductivity of 10 W/m·K and in-plane conductivity of 150 W/m·K 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. The optional Adhesive “A” coating offered on HT-1205 and HT-1210 is not available on the HT-1220 grade.
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 ASTM C6111.4 (electrical resistivity).
What differentiates HT-1220 from the thinner HT-1205 / HT-1210 grades or the polymer-enhanced HT-2500 series?
HT-1220 is the 0.51 mm pure graphite grade — the thickest in the HT-1200 series — and is selected when the assembly needs additional bulk to bridge larger bondline gaps than the 0.127 mm HT-1205 or 0.25 mm HT-1210 can fill. The pure graphite construction provides a much wider operating range (-40°C to +400°C) than the polymer-enhanced HT-2500 series (-25°C to +125°C). One trade-off specific to HT-1220 is that the optional Adhesive "A" coating offered on HT-1205 and HT-1210 is not available on this grade.
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, which determines real-world performance at a given bondline and pressure. HT-1220 provides 10 W/m·K through-plane and 150 W/m·K in-plane at 700 kPa, supporting both vertical heat extraction and lateral spreading. The TDS does not list thermal impedance values at 200 kPa or 700 kPa for HT-1220.
What is the operating temperature range for HT-1220?
The operating temperature range is -40°C to +400°C.
Is HT-1220 suitable for flame-rated and RoHS-regulated environments?
Yes. HT-1220 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-1220 be specified?
Specify grade (HT-1220), thickness (0.51 mm), part geometry (die-cut, kiss-cut, or sheet), compliance requirements (UL 94 V-0, RoHS, halogen free, lead free), dimensional tolerances, and finished format. Note that the Adhesive "A" coating option is not available on this grade.
