Graphite PYRO
Grade
PYRO = pyrolytic graphite
Use for thermal-spreader, crucible-liner and thermal-barrier duty where extreme in-plane conductivity plus through-plane insulation and zero permeability are needed.
Values for the PYRO condition
Other Graphite tempers and conditions
Graphite is listed in 2 conditions; see the grade overview at Graphite.
- MLD
- PYRO
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Die/vibration-moulded medium-grain graphite | Cost-effective medium-grain grade for large moulds, casting dies, sintering trays and roughing EDM electrodes. | — | 20 | — | — | 120 W/m·K |
PYROThis page Pyrolytic graphite | Use for thermal-spreader, crucible-liner and thermal-barrier duty where extreme in-plane conductivity plus through-plane insulation and zero permeability are needed. | — | 90 | — | — | 400 W/m·K |
What is Graphite PYRO?
Graphite PYRO is Graphite in the PYRO grade — use for thermal-spreader, crucible-liner and thermal-barrier duty where extreme in-plane conductivity plus through-plane insulation and zero permeability are needed. Graphite PYRO has a tensile strength of 90 MPa (13.1 ksi), weaker than 52% of ceramic grades. The elastic modulus is 30 GPa (4.35 Msi). Graphite PYRO has a density of 2.2 g/cm³ (0.0795 lb/in³), lighter than 87% of ceramic grades. It melts at 3,650°C (6,602 °F).
Advantages
- Conducts heat well — 400 W/m·K (231.1 BTU/hr·ft·°F), better than 99% of ceramic grades
- Lightweight — 2.2 g/cm³ (0.0795 lb/in³), better than 87% of ceramic grades
- Easy to machine — 45/100, better than 86% of ceramic grades
Limitations
- Hard to polish — 35/100, worse than 93% of ceramic grades
- Low stiffness — 30 GPa (4.35 Msi), worse than 87% of ceramic grades
- Low fracture toughness — 1 MPa·√m (0.91 ksi·√in), worse than 84% of ceramic grades
Graphite PYRO properties
Typical room-temperature values for Graphite PYRO; 11 are specific to this condition. Other listed values are Graphite reference data and may not represent this condition. Bars are the position among ceramic grades.
Physical3
Graphite PYRO has a density of 2.2 g/cm³ (0.0795 lb/in³), lighter than 87% of ceramic grades. It melts at 3,650°C (6,602 °F).
Mechanical10
Graphite PYRO has a tensile strength of 90 MPa (13.1 ksi), weaker than 52% of ceramic grades. The elastic modulus is 30 GPa (4.35 Msi).
Thermal5
Graphite PYRO is rated for continuous service to 500°C (932 °F). It conducts heat at 400 W/m·K (231.1 BTU/hr·ft·°F), better than 99% of ceramic grades. Thermal expansion is 1 µm/m·K (0.556 µin/in·°F).
Electrical2
Graphite PYRO has an electrical resistivity of 5×10⁻⁶ Ω·m.
Chemical & Environmental2
Corrosion resistance is very good (80/100), better than 56% of ceramic grades.
Sustainability4
Producing a kilogram of Graphite PYRO takes about 120 MJ of energy and emits 9 kg of CO₂ — more than 51% of ceramic grades. Typical recycled content is 10%.
Manufacturability3
Graphite PYRO's machinability is fair (45/100, better than 86% of ceramic grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Graphite PYRO
Is Graphite easy to machine?
Machines dry and fast with carbide or PCD tooling (no coolant); requires vacuum dust extraction and sharp tools since the dust is abrasive and electrically conductive.
Can Graphite be welded?
Not weldable — parts are joined mechanically (graphite bolts/threads) or with carbon/graphite cement cured and re-baked.
Can Graphite be formed, bent or molded?
Net shape comes from cold isostatic pressing, extrusion or vibration moulding of coke/pitch mix, then baking ~1000 °C, optional pitch re-impregnation and graphitization at 2600–3000 °C; final geometry is achieved by machining, not forming.
What surface finishes work on Graphite?
Common finishes are resin/metal impregnation for imperviousness, halogen purification to <20 ppm ash, and CVD SiC or pyrolytic-carbon coating for oxidation and particle-shedding control; no plating or painting.
Graphite 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 |
|---|---|---|
| ashresidual Si, Al, Fe, Ca, V oxides; halogen-purified grades <20 ppm | 0 – 0.3 | 0.05 |
| Sfrom petroleum/needle coke feedstock | ≤ 0.05 | 0.02 |
| phenolic resin impregnantonly in impervious (RI) variant | 0 – 15 | 0 |
| Cfixed carbon after graphitization; purified grades reach ≥99.99 % | ≥ 99 (balance) | — |
Graphite PYRO — frequently asked
What is Graphite PYRO used for?
Graphite PYRO is typically used for EDM electrodes, continuous casting molds, crucibles, semiconductor furnace parts and electrodes. In short: fastest-machining ceramic material; self-lubricating high-temperature carbon; standard EDM electrode material.
What is the tensile strength of Graphite PYRO?
Graphite PYRO has a typical tensile strength of 90 MPa (13.1 ksi) — weaker than 52% of ceramic grades. Strength varies by condition: see the 2 listed tempers.
Is Graphite PYRO easy to machine?
Reasonably — machinability is rated fair (45/100, better than 86% of ceramic grades). Machines dry and fast with carbide or PCD tooling (no coolant); requires vacuum dust extraction and sharp tools since the dust is abrasive and electrically conductive.
Can Graphite PYRO be welded?
Not weldable — parts are joined mechanically (graphite bolts/threads) or with carbon/graphite cement cured and re-baked.
What surface finishes work on Graphite PYRO?
Common finishes are resin/metal impregnation for imperviousness, halogen purification to <20 ppm ash, and CVD SiC or pyrolytic-carbon coating for oxidation and particle-shedding control; no plating or painting.
Can Graphite PYRO be formed, bent or molded?
Net shape comes from cold isostatic pressing, extrusion or vibration moulding of coke/pitch mix, then baking ~1000 °C, optional pitch re-impregnation and graphitization at 2600–3000 °C; final geometry is achieved by machining, not forming.
What is the maximum service temperature of Graphite PYRO?
Graphite PYRO is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM C709 — Standard Terminology Relating to Manufactured Carbon and Graphite — ASTM International (2021)
- ASTM C651 / C695 / C749 / C611 — flexural, compressive, tensile and resistivity test methods for graphite — ASTM International (2020)
- IG-11 / ISO-88 isotropic graphite property sheets — Toyo Tanso (2022)
- EDM-3 / AXF-5Q ultrafine graphite properties — Entegris (POCO Graphite) (2021)
- Specialty graphite grades R6650, R6300, extruded grades — SGL Carbon (2022)
- Impervious graphite (Graphilor) and isostatic grade data — Mersen (2021)
- Engineered Materials Handbook Vol. 4 — Ceramics and Glasses / carbon-graphite properties — ASM International (1991)
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.