Huahao Sealing · Carbon Graphite Components
Carbon graphite is a high-purity carbon-based material made from petroleum coke and pitch coke through mixing, forming and baking. Huahao Sealing supplies multiple carbon graphite grades with density 1.55-1.85 g/cm³, temperature range -200 to 600°C, featuring natural self-lubrication, chemical inertness and high thermal conductivity for mechanical seal rings, bushings and bearings.
| Density | 1.55 – 1.85 g/cm³ |
| Temperature | -200°C ~ 600°C (grade dependent) |
| Compressive Strength | 150 – 350 MPa |
| Shore Hardness | 60 – 95 HS |
| Thermal Conductivity | 8 – 70 W/m·K |
| Coefficient of Friction | 0.04 – 0.15 (dry) |
| pH Resistance | 0 – 14 (grade dependent) |
| Porosity | 8 – 15% (before impregnation) |
Natural self-lubrication — layered graphite crystal structure forms a transfer film at the friction interface, friction coefficient as low as 0.04, no external lubrication required
Chemical inertness — resists most acids, alkalis, salts and organic solvents, stable across pH 0-14
High thermal conductivity — 8-70 W/m·K, several times that of metal bearings, dissipates heat rapidly to prevent hot spots
High temperature resistance — anti-oxidation treatment enables stable 600°C continuous operation, 700°C short-term peak
Machinability — precision turning, milling and grinding to micron-level tolerances for custom non-standard geometries
Mechanical seal rings — face seals for centrifugal pumps, chemical pumps and oil pumps
Carbon graphite bushings — pump shaft support sleeves replacing metallic bushings
Carbon graphite bearings — high-temperature, dry-running and corrosive-media applications
Compressor seal rings — piston rod and shaft sealing
Agitator bearings — reactor vessel stirring shaft support
| Grade Code | Temperature | Notes |
|---|---|---|
| M106 | 350°C | Standard carbon graphite, general-purpose seals and bearings |
| M106K | 220°C | Resin-impregnated, food-grade, FDA compliant |
| M106H | 500°C | Antimony-impregnated, high-temp anti-oxidation |
| M191T | 600°C | Carbonized, extreme chemical inertness |
Carbon graphite is a baked engineering material with 8-15% porosity that requires impregnation for seal applications. Natural or expandable graphite has weak interlayer bonding and is unsuitable for precision machining. The term 'carbon graphite' in the sealing industry refers to baked and impregnated engineering carbon graphite.
It depends on the grade. Standard carbon graphite 350°C, resin-impregnated (M106K) 220°C, antimony-impregnated (M106H) 500°C, carbonized (M191T) 600°C. Above 400°C, metal-impregnated or carbonized grades with anti-oxidation treatment are required.
Unimpregnated carbon graphite density is 1.55-1.70 g/cm³. After resin impregnation 1.75-1.80 g/cm³, after antimony impregnation 1.80-1.85 g/cm³. Higher density means lower porosity and better mechanical strength and wear resistance.
In the layered crystal structure of carbon graphite, carbon atoms are bonded by strong covalent bonds within layers and weak van der Waals forces between layers. During friction, layers slide easily and form a transfer film on the mating surface, reducing the friction coefficient to 0.04-0.15.
