UHP Graphite Electrode NIPPLE
Grade
NIPPLE = uHP nipple / connecting pin
Choose the multiply impregnated and rebaked high-density joint stock, about twice the strength of the electrode body at 15 MPa tensile, for tapered threaded connections.
Values for the NIPPLE condition
Other UHP Graphite Electrode tempers and conditions
UHP Graphite Electrode is listed in 5 conditions; see the grade overview at UHP Graphite Electrode.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
UHP Φ650–800 mm | Pick the Φ650–800 mm size for very large AC arc furnaces and DC furnace cathodes at the highest current per electrode; it places the strictest demands on needle-coke quality. | — | 7 | 0.15 | — | 160 W/m·K |
UHP Φ550–600 mm | Use the Φ550–600 mm size on large high-power arc furnaces where maximum current per electrode is required; tensile strength (7.5 MPa) and bulk density are slightly below smaller diameters. | — | 8 | 0.17 | — | 165 W/m·K |
UHP-450Default UHP Φ450–500 mm | Choose the Φ450–500 mm size as the most widely used option for 50–100 t arc furnaces, balancing performance against price. | — | 8 | 0.18 | — | 170 W/m·K |
UHP Φ200–400 mm | Pick the Φ200–400 mm size for small and medium arc furnaces and LF refining ladles, where strength (9.5 MPa tensile) and electrical conductivity are the best in the diameter range. | — | 10 | 0.2 | — | 180 W/m·K |
NIPPLEThis page UHP nipple / connecting pin | Choose the multiply impregnated and rebaked high-density joint stock, about twice the strength of the electrode body at 15 MPa tensile, for tapered threaded connections. | — | 15 | — | — | 200 W/m·K |
What is UHP Graphite Electrode NIPPLE?
UHP Graphite Electrode NIPPLE is UHP Graphite Electrode in the NIPPLE grade — choose the multiply impregnated and rebaked high-density joint stock, about twice the strength of the electrode body at 15 MPa tensile, for tapered threaded connections. UHP Graphite Electrode NIPPLE has a tensile strength of 15 MPa (2.18 ksi), weaker than 90% of ceramic grades. Elongation at break is 0.18% and the elastic modulus is 18 GPa (2.61 Msi). UHP Graphite Electrode NIPPLE has a density of 1.8 g/cm³ (0.065 lb/in³), lighter than 89% of ceramic grades. It melts at 3,650°C (6,602 °F). UHP-450 is the default condition FabDigit quotes; NIPPLE is available on request or by drawing note.
Advantages
- High service temperature — 2,500°C (4,532 °F), better than 98% of ceramic grades
- Conducts heat well — 200 W/m·K (115.6 BTU/hr·ft·°F), better than 96% of ceramic grades
- Easy to machine — 85/100, better than 91% of ceramic grades
- Lightweight — 1.8 g/cm³ (0.065 lb/in³), better than 89% of ceramic grades
- Ductile — tolerates forming and impact — 0.18%, better than 77% of ceramic grades
Limitations
- Low stiffness — 18 GPa (2.61 Msi), worse than 87% of ceramic grades
- Low fracture toughness — 1 MPa·√m (0.91 ksi·√in), worse than 84% of ceramic grades
UHP Graphite Electrode NIPPLE properties
Typical room-temperature values for UHP Graphite Electrode NIPPLE; 11 are specific to this condition. Other listed values are UHP Graphite Electrode reference data and may not represent this condition. Bars are the position among ceramic grades.
Physical3
UHP Graphite Electrode NIPPLE has a density of 1.8 g/cm³ (0.065 lb/in³), lighter than 89% of ceramic grades. It melts at 3,650°C (6,602 °F).
Mechanical9
UHP Graphite Electrode NIPPLE has a tensile strength of 15 MPa (2.18 ksi), weaker than 90% of ceramic grades. Elongation at break is 0.18% and the elastic modulus is 18 GPa (2.61 Msi).
Thermal5
UHP Graphite Electrode NIPPLE is rated for continuous service to 2,500°C (4,532 °F). It conducts heat at 200 W/m·K (115.6 BTU/hr·ft·°F), better than 96% of ceramic grades. Thermal expansion is 0.6 µm/m·K (0.333 µin/in·°F).
Electrical2
UHP Graphite Electrode NIPPLE has an electrical resistivity of 4.3×10⁻⁶ Ω·m.
Chemical & Environmental2
Corrosion resistance is very good (75/100), better than 50% of ceramic grades.
Sustainability3
Producing a kilogram of UHP Graphite Electrode NIPPLE takes about 130 MJ of energy and emits 6 kg of CO₂ — more than 55% of ceramic grades. Typical recycled content is 0%.
Manufacturability2
UHP Graphite Electrode NIPPLE's machinability is excellent (85/100, better than 91% of ceramic grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with UHP Graphite Electrode NIPPLE
Is UHP Graphite Electrode easy to machine?
Turns and mills very easily dry with carbide or diamond tooling. The dust is abrasive and electrically conductive, so extraction and machine protection are mandatory; tapered socket threads are cut on dedicated machines.
Can UHP Graphite Electrode be welded?
Not weldable; electrode columns are joined by tapered threaded nipples (3TPI/4TPI) tightened to the specified torque.
Can UHP Graphite Electrode be formed, bent or molded?
Needle coke and pitch are mixed and kneaded, extruded, baked, then pitch-impregnated and re-baked one to three times, followed by graphitisation at 2800–3000 °C. The finished body cannot be formed further.
What surface finishes work on UHP Graphite Electrode?
After machining to tolerance, an antioxidant coating (SiC or phosphate) can be sprayed on, or a spray-cooling ring fitted, to reduce side-wall oxidation loss.
UHP Graphite Electrode 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 |
|---|---|---|
| ashGB/T 3079 UHP ash ≤0.3 % | ≤ 0.3 | 0.15 |
| Sfrom needle coke; excess causes graphitization puffing | ≤ 0.06 | 0.03 |
| volatilesvolatile matter | ≤ 0.2 | 0.1 |
| Cneedle coke + coal-tar pitch binder, graphitized at 2800–3000 °C | ≥ 99.5 (balance) | — |
UHP Graphite Electrode NIPPLE — frequently asked
What is UHP Graphite Electrode NIPPLE used for?
UHP Graphite Electrode NIPPLE is typically used for EAF steelmaking electrodes, ladle furnace electrodes and high-current arc furnaces. In short: highest current-carrying electrode; lowest-resistivity graphite grade; needle-coke UHP class.
What is the tensile strength of UHP Graphite Electrode NIPPLE?
UHP Graphite Electrode NIPPLE has a typical tensile strength of 15 MPa (2.18 ksi) — weaker than 90% of ceramic grades. Strength varies by condition: see the 5 listed tempers.
Is UHP Graphite Electrode NIPPLE easy to machine?
Yes — machinability is rated excellent (85/100, better than 91% of ceramic grades). Turns and mills very easily dry with carbide or diamond tooling. The dust is abrasive and electrically conductive, so extraction and machine protection are mandatory; tapered socket threads are cut on dedicated machines.
Can UHP Graphite Electrode NIPPLE be welded?
Not weldable; electrode columns are joined by tapered threaded nipples (3TPI/4TPI) tightened to the specified torque.
What surface finishes work on UHP Graphite Electrode NIPPLE?
After machining to tolerance, an antioxidant coating (SiC or phosphate) can be sprayed on, or a spray-cooling ring fitted, to reduce side-wall oxidation loss.
Can UHP Graphite Electrode NIPPLE be formed, bent or molded?
Needle coke and pitch are mixed and kneaded, extruded, baked, then pitch-impregnated and re-baked one to three times, followed by graphitisation at 2800–3000 °C. The finished body cannot be formed further.
What is the maximum service temperature of UHP Graphite Electrode NIPPLE?
UHP Graphite Electrode NIPPLE is rated for continuous use to about 2,500°C (4,532 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- GB/T 3079 (2018)
- JIS R7601 — JISC (2015)
- ASTM C709 Standard Terminology Relating to Manufactured Carbon and Graphite — ASTM (2021)
- UHP graphite electrode technical data — / / GrafTech (2023)
- Engineered Materials Handbook — Ceramics and Glasses (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.