Isostatic Graphite HP-5N
Grade
HP-5N = halogen-purified high-purity grade
Use the halogen-purified grade (ash < 5 ppm) for monocrystalline silicon and sapphire hot zones, crucibles, epitaxy and semiconductor fixtures where metal contamination is prohibited.
Values for the HP-5N condition
Other Isostatic Graphite tempers and conditions
Isostatic Graphite is listed in 4 conditions; see the grade overview at Isostatic Graphite.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
FG-10Default Fine grain (~10–20 µm), general-purpose isostatic graphite | Use the fine-grain (~10–20 µm) general-purpose grade as the cost-effective choice for roughing EDM electrodes, continuous-casting moulds, heating elements and general hot-zone parts. | — | 27 | — | — | 105 W/m·K |
HP-5NThis page Halogen-purified high-purity grade | Use the halogen-purified grade (ash < 5 ppm) for monocrystalline silicon and sapphire hot zones, crucibles, epitaxy and semiconductor fixtures where metal contamination is prohibited. | — | 27 | — | — | 120 W/m·K |
Ultra-fine grain (~5 µm) EDM electrode grade | Pick the ultra-fine-grain (~5 µm) grade as the mainstream EDM electrode material for stable discharge, low electrode wear and moderately fine rib detail. | — | 35 | — | — | 90 W/m·K |
Superfine grain (≤2 µm), high-density precision grade | Choose the superfine-grain (≤2 µm) high-density grade for mirror-finish and micro EDM electrodes, optical moulds and fine structures needing 55 MPa tensile strength and the finest discharge texture. | — | 55 | — | — | 70 W/m·K |
What is Isostatic Graphite HP-5N?
Isostatic Graphite HP-5N is Isostatic Graphite in the HP-5N grade — use the halogen-purified grade (ash < 5 ppm) for monocrystalline silicon and sapphire hot zones, crucibles, epitaxy and semiconductor fixtures where metal contamination is prohibited. Isostatic Graphite HP-5N has a tensile strength of 27 MPa (3.92 ksi), weaker than 82% of ceramic grades. The elastic modulus is 11 GPa (1.6 Msi). Isostatic Graphite HP-5N has a density of 1.78 g/cm³ (0.0643 lb/in³), lighter than 90% of ceramic grades. It melts at 3,650°C (6,602 °F). FG-10 is the default condition FabDigit quotes; HP-5N is available on request or by drawing note.
Advantages
- Easy to machine — 90/100, better than 94% of ceramic grades
- Lightweight — 1.78 g/cm³ (0.0643 lb/in³), better than 90% of ceramic grades
- Conducts heat well — 120 W/m·K (69.3 BTU/hr·ft·°F), better than 88% of ceramic grades
Limitations
- Low stiffness — 11 GPa (1.6 Msi), worse than 91% of ceramic grades
- Hard to polish — 45/100, worse than 88% of ceramic grades
- Low fracture toughness — 1 MPa·√m (0.91 ksi·√in), worse than 84% of ceramic grades
- Limited service temperature — 450°C (842 °F), worse than 77% of ceramic grades
Isostatic Graphite HP-5N properties
Typical room-temperature values for Isostatic Graphite HP-5N; 12 are specific to this condition. Other listed values are Isostatic Graphite reference data and may not represent this condition. Bars are the position among ceramic grades.
Physical3
Isostatic Graphite HP-5N has a density of 1.78 g/cm³ (0.0643 lb/in³), lighter than 90% of ceramic grades. It melts at 3,650°C (6,602 °F).
Mechanical10
Isostatic Graphite HP-5N has a tensile strength of 27 MPa (3.92 ksi), weaker than 82% of ceramic grades. The elastic modulus is 11 GPa (1.6 Msi).
Thermal5
Isostatic Graphite HP-5N is rated for continuous service to 450°C (842 °F). It conducts heat at 120 W/m·K (69.3 BTU/hr·ft·°F), better than 88% of ceramic grades. Thermal expansion is 4.5 µm/m·K (2.5 µin/in·°F).
Electrical2
Isostatic Graphite HP-5N has an electrical resistivity of 1×10⁻⁵ Ω·m.
Chemical & Environmental2
Corrosion resistance is very good (80/100), better than 56% of ceramic grades.
Sustainability4
Producing a kilogram of Isostatic Graphite HP-5N takes about 190 MJ of energy and emits 16 kg of CO₂ — more than 62% of ceramic grades. Typical recycled content is 5%.
Manufacturability3
Isostatic Graphite HP-5N'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 Isostatic Graphite HP-5N
Is Isostatic Graphite easy to machine?
Cut dry with no coolant, using carbide or PCD tooling at high spindle speed and light feed. Explosion-rated vacuum dust extraction is required, and exit edges should be chamfered to prevent break-out.
Can Isostatic Graphite be welded?
Not weldable; assemblies are made with graphite threaded joints, graphite tenon joints, or carbon cement with a carbonising binder.
Can Isostatic Graphite be formed, bent or molded?
Shaped only by machining or wire EDM from pressed and graphitised blanks; no plastic forming is possible. Large parts must be nested to the available blank sizes.
What surface finishes work on Isostatic Graphite?
Grind to final size and ultrasonically clean to remove residual dust. For oxidation resistance apply SiC, pyrolytic-carbon or CVD coatings, or phosphate impregnation; high-purity applications require halogen-atmosphere purification.
Isostatic 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 |
|---|---|---|
| ashstandard grade ash ≤500–1000 ppm; halogen-purified <5 ppm (HP-5N) | 5×10⁻⁴ – 0.1 | 0.03 |
| Sresidual sulfur, very low after graphitization | ≤ 0.03 | 0.01 |
| Femain metallic ash impurity; <1 ppm in purified grades | ≤ 0.01 | 0 |
| Cfixed carbon; needle/pitch coke + pitch binder, 2800–3000 °C | ≥ 99.9 (balance) | — |
Isostatic Graphite HP-5N — frequently asked
What is Isostatic Graphite HP-5N used for?
Isostatic Graphite HP-5N is typically used for EDM electrodes, hot-press molds, semiconductor fixtures and continuous casting dies. In short: finest-grain isotropic graphite; strongest common graphite grade; 5N purity available.
What is the tensile strength of Isostatic Graphite HP-5N?
Isostatic Graphite HP-5N has a typical tensile strength of 27 MPa (3.92 ksi) — weaker than 82% of ceramic grades. Strength varies by condition: see the 4 listed tempers.
Is Isostatic Graphite HP-5N easy to machine?
Yes — machinability is rated excellent (90/100, better than 94% of ceramic grades). Cut dry with no coolant, using carbide or PCD tooling at high spindle speed and light feed. Explosion-rated vacuum dust extraction is required, and exit edges should be chamfered to prevent break-out.
Can Isostatic Graphite HP-5N be welded?
Not weldable; assemblies are made with graphite threaded joints, graphite tenon joints, or carbon cement with a carbonising binder.
What surface finishes work on Isostatic Graphite HP-5N?
Grind to final size and ultrasonically clean to remove residual dust. For oxidation resistance apply SiC, pyrolytic-carbon or CVD coatings, or phosphate impregnation; high-purity applications require halogen-atmosphere purification.
Can Isostatic Graphite HP-5N be formed, bent or molded?
Shaped only by machining or wire EDM from pressed and graphitised blanks; no plastic forming is possible. Large parts must be nested to the available blank sizes.
What is the maximum service temperature of Isostatic Graphite HP-5N?
Isostatic Graphite HP-5N is rated for continuous use to about 450°C (842 °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 (2021)
- ASTM C651 / C695 / C749 — Flexural, Compressive and Tensile Testing of Graphite — ASTM (2020)
- IG-11 / IG-43 / IG-56 Isotropic Graphite Property Sheets — Toyo Tanso (2022)
- SIGRAFINE isostatic graphite grades (R6650, R6710) — SGL Carbon (2022)
- Properties and Characteristics of Graphite (EDM-3, EDM-AF5) — POCO Graphite / Entegris (2015)
- ASM Engineered Materials Handbook Vol. 4 — Ceramics and Glasses (carbon & graphite) — 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.