EG Carbon Brush EG-HD
Grade
EG-HD = fine-grain high-density electrographite for high current density
Pick for heavily loaded generators/slip rings needing higher current density and lower wear, at the cost of price and slightly harder commutator action.
Values for the EG-HD condition
Other EG Carbon Brush tempers and conditions
EG Carbon Brush is listed in 2 conditions; see the grade overview at EG Carbon Brush.
- EG-I
- EG-HD
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Resin/oil-impregnated electrographite | Choose when the machine runs in dry air, high altitude or vacuum-adjacent conditions where an untreated brush would dust badly. | — | 20 | 0.2 | 40 HV | 35 W/m·K |
EG-HDThis page Fine-grain high-density electrographite for high current density | Pick for heavily loaded generators/slip rings needing higher current density and lower wear, at the cost of price and slightly harder commutator action. | — | 25 | — | — | 80 W/m·K |
What is EG Carbon Brush EG-HD?
EG Carbon Brush EG-HD is EG Carbon Brush in the EG-HD grade — pick for heavily loaded generators/slip rings needing higher current density and lower wear, at the cost of price and slightly harder commutator action. EG Carbon Brush EG-HD has a tensile strength of 25 MPa (3.63 ksi), weaker than 85% of ceramic grades. The elastic modulus is 13 GPa (1.89 Msi). EG Carbon Brush EG-HD has a density of 1.82 g/cm³ (0.0658 lb/in³), lighter than 88% of ceramic grades. It melts at 3,650°C (6,602 °F).
Advantages
- Easy to machine — 85/100, better than 91% of ceramic grades
- Lightweight — 1.82 g/cm³ (0.0658 lb/in³), better than 88% of ceramic grades
- Conducts heat well — 80 W/m·K (46.2 BTU/hr·ft·°F), better than 77% of ceramic grades
Limitations
- Hard to polish — 35/100, worse than 93% of ceramic grades
- Low stiffness — 13 GPa (1.89 Msi), 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 — 400°C (752 °F), worse than 81% of ceramic grades
EG Carbon Brush EG-HD properties
Typical room-temperature values for EG Carbon Brush EG-HD; 12 are specific to this condition. Other listed values are EG Carbon Brush reference data and may not represent this condition. Bars are the position among ceramic grades.
Physical3
EG Carbon Brush EG-HD has a density of 1.82 g/cm³ (0.0658 lb/in³), lighter than 88% of ceramic grades. It melts at 3,650°C (6,602 °F).
Mechanical9
EG Carbon Brush EG-HD has a tensile strength of 25 MPa (3.63 ksi), weaker than 85% of ceramic grades. The elastic modulus is 13 GPa (1.89 Msi).
Thermal5
EG Carbon Brush EG-HD is rated for continuous service to 400°C (752 °F). It conducts heat at 80 W/m·K (46.2 BTU/hr·ft·°F), better than 77% of ceramic grades. Thermal expansion is 4 µm/m·K (2.22 µin/in·°F).
Electrical2
EG Carbon Brush EG-HD has an electrical resistivity of 2×10⁻⁵ Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (85/100), better than 69% of ceramic grades.
Sustainability4
Producing a kilogram of EG Carbon Brush EG-HD takes about 130 MJ of energy and emits 9 kg of CO₂ — more than 55% of ceramic grades. Typical recycled content is 5%.
Manufacturability3
EG Carbon Brush EG-HD'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 EG Carbon Brush EG-HD
Is EG Carbon Brush easy to machine?
Machines very easily dry with sharp carbide or PCD tooling — no coolant, but vacuum dust extraction and edge support are mandatory to avoid chipping.
Can EG Carbon Brush be welded?
Not weldable; brush shunts are attached by tamping copper stranded wire into a drilled hole with copper powder, or by soldering to a metallized pad.
Can EG Carbon Brush be formed, bent or molded?
Formed by mixing coke/pitch, pressing or extruding a green block, baking ~1000 °C, then graphitizing at 2500–2800 °C; final shape is ground/milled from stock, not net-shape formed.
What surface finishes work on EG Carbon Brush?
Bedded to the commutator with abrasive brush-seating stone; surfaces may be resin-impregnated, copper-plated at the top face, or sealed against dusting.
EG Carbon Brush 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 (SiO2, Fe2O3, Al2O3 etc.)residual mineral ash after graphitization | 0.05 – 1 | 0.4 |
| impregnant (resin/oil)only in treated EG-I grades | 0 – 8 | 0 |
| Cgraphitized carbon from calcined petroleum coke / lampblack plus pitch binder | ≥ 98 (balance) | — |
EG Carbon Brush EG-HD — frequently asked
What is EG Carbon Brush EG-HD used for?
EG Carbon Brush EG-HD is typically used for motor and generator brushes, slip-ring contacts and traction motors. In short: best commutation at speed; low friction, low wear; higher resistance than metal-graphite.
What is the tensile strength of EG Carbon Brush EG-HD?
EG Carbon Brush EG-HD has a typical tensile strength of 25 MPa (3.63 ksi) — weaker than 85% of ceramic grades. Strength varies by condition: see the 2 listed tempers.
Is EG Carbon Brush EG-HD easy to machine?
Yes — machinability is rated excellent (85/100, better than 91% of ceramic grades). Machines very easily dry with sharp carbide or PCD tooling — no coolant, but vacuum dust extraction and edge support are mandatory to avoid chipping.
Can EG Carbon Brush EG-HD be welded?
Not weldable; brush shunts are attached by tamping copper stranded wire into a drilled hole with copper powder, or by soldering to a metallized pad.
What surface finishes work on EG Carbon Brush EG-HD?
Bedded to the commutator with abrasive brush-seating stone; surfaces may be resin-impregnated, copper-plated at the top face, or sealed against dusting.
Can EG Carbon Brush EG-HD be formed, bent or molded?
Formed by mixing coke/pitch, pressing or extruding a green block, baking ~1000 °C, then graphitizing at 2500–2800 °C; final shape is ground/milled from stock, not net-shape formed.
What is the maximum service temperature of EG Carbon Brush EG-HD?
EG Carbon Brush EG-HD is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- JIS C 2802 Carbon brushes for electrical machines — JSA (2016)
- GB/T 1416 (Carbon brushes) — SAC (2019)
- ASM Engineered Materials Handbook Vol.4 — Ceramics and Glasses (carbon/graphite section) — ASM International (1991)
- Electrographite brush grade data sheets — Mersen / Schunk / (2023)
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.