Natural Flake Graphite FC99
Grade
FC99 = 99 % C, chemically purified flake
Acid/alkali-leached grade for conductive fillers, carbon brushes, seals and lubricant additives where ash below ~1 % matters.
Values for the FC99 condition
Other Natural Flake Graphite tempers and conditions
Natural Flake Graphite is listed in 4 conditions; see the grade overview at Natural Flake Graphite.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
FC94Default 94–95 % C, medium/fine flake | Standard flotation-concentrate grade for refractories, foundry coatings, brake pads and pencil/lubricant use — best cost per unit carbon. | — | 8 | 0.3 | 12 HV | 250 W/m·K |
FC99This page 99 % C, chemically purified flake | Acid/alkali-leached grade for conductive fillers, carbon brushes, seals and lubricant additives where ash below ~1 % matters. | — | 8 | 0.4 | 8 HV | 350 W/m·K |
99.95 % C, high-purity | Ultra-low-ash grade — feedstock for spheroidised Li-ion anode material, nuclear/semiconductor parts and premium expanded-graphite foil. | — | 8 | 0.5 | 7 HV | 450 W/m·K |
95 % C, large flake | Coarse, high-aspect-ratio flake commanding a premium — the feedstock for expandable graphite, graphite foil/gaskets and high-end refractories. | — | 9 | 0.4 | 10 HV | 400 W/m·K |
What is Natural Flake Graphite FC99?
Natural Flake Graphite FC99 is Natural Flake Graphite in the FC99 grade — acid/alkali-leached grade for conductive fillers, carbon brushes, seals and lubricant additives where ash below ~1 % matters. Natural Flake Graphite FC99 has a tensile strength of 8 MPa (1.16 ksi), weaker than 93% of ceramic grades. Elongation at break is 0.4% and the elastic modulus is 11 GPa (1.6 Msi). Natural Flake Graphite FC99 has a density of 2.25 g/cm³ (0.0813 lb/in³), lighter than 86% of ceramic grades. It melts at 3,650°C (6,602 °F). FC94 is the default condition FabDigit quotes; FC99 is available on request or by drawing note.
Advantages
- Conducts heat well — 350 W/m·K (202.2 BTU/hr·ft·°F), better than 99% of ceramic grades
- Ductile — tolerates forming and impact — 0.4%, better than 96% of ceramic grades
- Easy to machine — 90/100, better than 94% of ceramic grades
- Low embodied carbon — 2.5 kg CO₂/kg, better than 92% of ceramic grades
- Lightweight — 2.25 g/cm³ (0.0813 lb/in³), better than 86% of ceramic grades
Limitations
- Low fracture toughness — 0.85 MPa·√m (0.774 ksi·√in), worse than 98% of ceramic grades
- Low stiffness — 11 GPa (1.6 Msi), worse than 91% of ceramic grades
Natural Flake Graphite FC99 properties
Typical room-temperature values for Natural Flake Graphite FC99; 15 are specific to this condition. Other listed values are Natural Flake Graphite reference data and may not represent this condition. Bars are the position among ceramic grades.
Physical2
Natural Flake Graphite FC99 has a density of 2.25 g/cm³ (0.0813 lb/in³), lighter than 86% of ceramic grades. It melts at 3,650°C (6,602 °F).
Mechanical12
Natural Flake Graphite FC99 has a tensile strength of 8 MPa (1.16 ksi), weaker than 93% of ceramic grades. Elongation at break is 0.4% and the elastic modulus is 11 GPa (1.6 Msi).
Thermal5
Natural Flake Graphite FC99 is rated for continuous service to 500°C (932 °F). It conducts heat at 350 W/m·K (202.2 BTU/hr·ft·°F), better than 99% of ceramic grades. Thermal expansion is 1 µm/m·K (0.556 µin/in·°F).
Electrical2
Natural Flake Graphite FC99 has an electrical resistivity of 4.5×10⁻⁶ Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (88/100), better than 77% of ceramic grades.
Sustainability4
Producing a kilogram of Natural Flake Graphite FC99 takes about 30 MJ of energy and emits 2.5 kg of CO₂ — less than 94% of ceramic grades. Typical recycled content is 0%.
Manufacturability1
Natural Flake Graphite FC99's machinability is excellent (90/100, better than 94% of ceramic grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Natural Flake Graphite FC99
Is Natural Flake Graphite easy to machine?
Supplied as powder — not machined; processing is milling, air classification, spheroidisation and screening, with dust control (combustible dust, low ignition energy) and no lubricants that contaminate ash.
Can Natural Flake Graphite be welded?
Not weldable; joining of graphite bodies made from this powder relies on carbonaceous cements, resin/pitch binders or mechanical clamping.
Can Natural Flake Graphite be formed, bent or molded?
Blended with pitch, resin, clay or metal binders and pressed/extruded/isostatically compacted; intercalated flake is exfoliated then roll-formed into flexible graphite foil without any binder.
What surface finishes work on Natural Flake Graphite?
Formed parts can be impregnated with resin or phosphate/CVD SiC coatings for oxidation protection; loose powder is dedusted, coated (pitch/carbon-coated for anodes) or surface-treated for wetting in polymer compounds.
Natural Flake 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 |
|---|---|---|
| Cfixed carbon on dry basis, GB/T 3521 method | 94 – 95 | 94.5 |
| moistureas-shipped | 0 – 0.5 | 0.3 |
| volatile matter | 0 – 1.2 | 0.8 |
| Shigher in acid-treated/expandable grades | 0 – 0.15 | 0.05 |
| Fepart of ash; <50 ppm in HP-9995 | 0 – 1 | 0.4 |
| ash (SiO2+Al2O3+Fe2O3+CaO)silicate gangue from ore | ≥ 4 (balance) | — |
Natural Flake Graphite FC99 — frequently asked
What is Natural Flake Graphite FC99 used for?
Natural Flake Graphite FC99 is typically used for lubricant additive, refractory brick additive, battery anode feedstock and foundry facings. In short: highest-conductivity natural graphite; feedstock for flexible foil; powder form, not stock shapes.
What is the tensile strength of Natural Flake Graphite FC99?
Natural Flake Graphite FC99 has a typical tensile strength of 8 MPa (1.16 ksi) — weaker than 93% of ceramic grades. Strength varies by condition: see the 4 listed tempers.
Is Natural Flake Graphite FC99 easy to machine?
Yes — machinability is rated excellent (90/100, better than 94% of ceramic grades). Supplied as powder — not machined; processing is milling, air classification, spheroidisation and screening, with dust control (combustible dust, low ignition energy) and no lubricants that contaminate ash.
Can Natural Flake Graphite FC99 be welded?
Not weldable; joining of graphite bodies made from this powder relies on carbonaceous cements, resin/pitch binders or mechanical clamping.
What surface finishes work on Natural Flake Graphite FC99?
Formed parts can be impregnated with resin or phosphate/CVD SiC coatings for oxidation protection; loose powder is dedusted, coated (pitch/carbon-coated for anodes) or surface-treated for wetting in polymer compounds.
Can Natural Flake Graphite FC99 be formed, bent or molded?
Blended with pitch, resin, clay or metal binders and pressed/extruded/isostatically compacted; intercalated flake is exfoliated then roll-formed into flexible graphite foil without any binder.
What is the maximum service temperature of Natural Flake Graphite FC99?
Natural Flake Graphite FC99 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
- GB/T 3518 (Flake graphite) (2008)
- GB/T 3521 (Chemical analysis of graphite) — SAC (2008)
- ASTM C561 Standard Test Method for Ash in a Graphite Sample — ASTM International (2019)
- ASM Engineered Materials Handbook, Vol. 4 — Ceramics and Glasses (carbon/graphite section) — ASM International (1991)
- CRC Handbook of Chemistry and Physics — properties of carbon (graphite) — CRC Press (2020)
- USGS Mineral Commodity Summaries — Graphite (natural) — U.S. Geological Survey (2024)
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.