Extruded Graphite
Extruded Graphite is a coarse-grain, anisotropic carbon made by extruding a coke/pitch paste, baking and graphitising, stocked as EG-M, EG-C, EG-F, EG-HP and EG-RI.
Reference datasheet — Extruded Graphite is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the EG-M condition
Extruded Graphite tempers and conditions
Extruded Graphite is supplied in 4 conditions, soft to hard. EG-M is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Coarse-grain extruded graphite | Cheapest large-diameter stock (electrode-type); choose when conductivity and size matter more than strength or surface finish. | 6 | 150 W/m·K | |||
EG-MDefault Medium-grain extruded graphite | General-purpose extruded stock for furnace parts, moulds, heating elements and rough EDM — best balance of price, size availability and strength. | 9 | 130 W/m·K | |||
Halogen-purified extruded graphite | Use for semiconductor, PV, sintering and vacuum-furnace hot zones where metallic contamination must be avoided. | 9 | 0.25 | 35 HV | 135 W/m·K | |
Fine-grain extruded graphite | Pick when detail features, tighter tolerance or higher strength are needed but isostatic grades are too expensive. | 14 | 110 W/m·K |
Supply forms, finishes and certifications
Ways Extruded Graphite is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
EG-RI | Resin-impregnated extruded graphite | Surface finish |
What is Extruded Graphite?
Extruded Graphite is a coarse-grain, anisotropic carbon made by extruding a coke/pitch paste, baking and graphitising, stocked as EG-M, EG-C, EG-F, EG-HP and EG-RI. It is the low-cost choice for electrodes, crucibles, heating elements and bushings in rod and large block form, with density 1.7 g/cm3, tensile strength 9 MPa, modulus 10 GPa, thermal conductivity 130 W/m·K and use to 2800 °C in inert or vacuum conditions. Properties differ with and across the extrusion direction, porosity is open unless impregnated, and it oxidises in air. Isostatic graphite is the alternative when isotropy and fine surface finish are needed. Extruded Graphite has a density of 1.7 g/cm³ (0.0614 lb/in³), lighter than 93% of ceramic grades. It melts at 3,650°C (6,602 °F). Extruded Graphite has a tensile strength of 9 MPa (1.31 ksi), weaker than 92% of ceramic grades. Elongation at break is 0.25% and the elastic modulus is 10 GPa (1.45 Msi).
What is Extruded Graphite used for?
- electrodes
- crucibles
- heating elements
- bushings
Advantages
- High service temperature — 2,800°C (5,072 °F), better than 99% of ceramic grades
- Lightweight — 1.7 g/cm³ (0.0614 lb/in³), better than 93% of ceramic grades
- Easy to machine — 88/100, better than 92% of ceramic grades
- Conducts heat well — 130 W/m·K (75.1 BTU/hr·ft·°F), better than 91% of ceramic grades
- Ductile — tolerates forming and impact — 0.25%, better than 85% of ceramic grades
Limitations
- Hard to polish — 20/100, worse than 99% of ceramic grades
- Low stiffness — 10 GPa (1.45 Msi), worse than 93% of ceramic grades
- Low fracture toughness — 1 MPa·√m (0.91 ksi·√in), worse than 84% of ceramic grades
Extruded Graphite properties
Typical room-temperature values for Extruded Graphite-EG-M; bars are the position among ceramic grades.
Physical3
Extruded Graphite has a density of 1.7 g/cm³ (0.0614 lb/in³), lighter than 93% of ceramic grades. It melts at 3,650°C (6,602 °F).
Mechanical10
Extruded Graphite has a tensile strength of 9 MPa (1.31 ksi), weaker than 92% of ceramic grades. Elongation at break is 0.25% and the elastic modulus is 10 GPa (1.45 Msi).
Thermal5
Extruded Graphite is rated for continuous service to 2,800°C (5,072 °F). It conducts heat at 130 W/m·K (75.1 BTU/hr·ft·°F), better than 91% of ceramic grades. Thermal expansion is 2.2 µm/m·K (1.22 µin/in·°F).
Electrical2
Extruded Graphite has an electrical resistivity of 8×10⁻⁶ Ω·m.
Chemical & Environmental2
Corrosion resistance is very good (80/100), better than 56% of ceramic grades.
Sustainability4
Producing a kilogram of Extruded Graphite takes about 120 MJ of energy and emits 7.5 kg of CO₂ — more than 51% of ceramic grades. Typical recycled content is 5%.
Manufacturability3
Extruded Graphite's machinability is excellent (88/100, better than 92% of ceramic grades).
Common Calculations4
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the ceramic family
Yield strength against density for every ceramic grade FabDigit runs. Extruded Graphite is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Extruded Graphite
Is Extruded Graphite easy to machine?
Cuts very easily dry with carbide or PCD tooling at high speed — never use coolant; conductive abrasive dust demands full vacuum extraction and sealed spindles, and sharp edges chip readily.
Can Extruded Graphite be welded?
Not weldable; parts are joined by graphite cement/carbonaceous adhesive, threaded graphite fittings or mechanical clamping.
Can Extruded Graphite be formed, bent or molded?
Formed only at the green stage by paste extrusion, then baked ~1000 °C and graphitised 2600–3000 °C; finished stock is brittle and must be net-machined, not bent or formed.
Extruded 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 |
|---|---|---|
| ash≤10 ppm (0.001 %) for halogen-purified grades | 0.02 – 0.5 | 0.2 |
| Sresidual sulphur from coke | ≤ 0.05 | 0.02 |
| Cpetroleum/needle coke aggregate + coal-tar pitch binder, graphitised | ≥ 99 (balance) |
What surface finishes work on Extruded Graphite?
Optional halogen purification, pyrolytic-carbon/SiC coating or resin/pitch impregnation to seal porosity; surface can be blasted or lapped but coarse grain limits attainable Ra.
How much does Extruded Graphite cost?
Extruded Graphite is a premium-cost ceramic ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Extruded Graphite — frequently asked
What is Extruded Graphite used for?
Extruded Graphite is typically used for electrodes, crucibles, heating elements and bushings. In short: lowest-cost graphite stock; large-section coarse-grain blanks; anisotropic extruded structure.
What is the tensile strength of Extruded Graphite?
Extruded Graphite has a typical tensile strength of 9 MPa (1.31 ksi) — weaker than 92% of ceramic grades. Strength varies by condition: see the 4 listed tempers.
Is Extruded Graphite easy to machine?
Yes — machinability is rated excellent (88/100, better than 92% of ceramic grades). Cuts very easily dry with carbide or PCD tooling at high speed — never use coolant; conductive abrasive dust demands full vacuum extraction and sealed spindles, and sharp edges chip readily.
Can Extruded Graphite be welded?
Not weldable; parts are joined by graphite cement/carbonaceous adhesive, threaded graphite fittings or mechanical clamping.
What surface finishes work on Extruded Graphite?
Optional halogen purification, pyrolytic-carbon/SiC coating or resin/pitch impregnation to seal porosity; surface can be blasted or lapped but coarse grain limits attainable Ra.
Can Extruded Graphite be formed, bent or molded?
Formed only at the green stage by paste extrusion, then baked ~1000 °C and graphitised 2600–3000 °C; finished stock is brittle and must be net-machined, not bent or formed.
What is the maximum service temperature of Extruded Graphite?
Extruded Graphite is rated for continuous use to about 2,800°C (5,072 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does Extruded Graphite cost?
Extruded Graphite is a premium-cost ceramic ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- Extruded graphite grade data (electrode and general-purpose grades) — SGL Carbon / Mersen / Toyo Tanso (2023)
- Engineered Materials Handbook Vol.4: Ceramics and Glasses — carbon and graphite — ASM International (1991)
- ASTM C709 / C781 — terminology and testing of manufactured carbon and graphite — ASTM (2021)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.