Custom machined carbon graphite bearings for high-temperature, dry running, and submerged applications. Specified through operating speed, load, temperature, and drawing review.
| Metric | Typical Range | Why It Matters |
|---|---|---|
| Maximum Operating Temperature | 250°C to 2500°C depending on grade and atmosphere | Oxidation limits standard carbon graphite to around 400°C-500°C in air. |
| Pressure-Velocity (PV) Limit | Varies by grade (e.g., 50,000 to 150,000 psi-fpm) | Exceeding the PV limit causes rapid wear and bearing failure. |
| Coefficient of Friction | 0.05 - 0.25 | Determines heat generation and efficiency in dry-running states. |
Source-reviewed on September 24, 2026. These boundaries support RFQ screening only.
Evidence: Resin impregnants degrade above ~200°C. Standard carbon oxidizes at 400°C-500°C in air. High-temperature environments require bare electrographite (if inert) or metal impregnants.
Action: Specify continuous and peak operating temperatures, and the surrounding atmosphere.
Source: Morgan Advanced Materials / Industry GuidelinesEvidence: High speeds combined with high loads exceed the heat dissipation capabilities of the bearing (dry PV limit ~15,000 psi-fpm).
Action: Provide exact shaft RPM and radial/axial loads. Allow engineering to verify the PV limit.
Source: Bearing design principles for self-lubricating materialsEvidence: While graphite does not swell in fluids, certain impregnants might be attacked by specific chemicals.
Action: List all process fluids to ensure both the carbon matrix and the impregnant are chemically compatible.
Source: Metcar / Industrial Chemical CompatibilityEvidence: A rough or soft shaft will rapidly abrade the self-lubricating graphite transfer film, leading to premature failure.
Action: Specify shaft hardness (preferably > 45 HRC) and surface finish (typically < 16 µin Ra).
Source: Bearing design principles for self-lubricating materialsPublic references checked on September 24, 2026.
| Decision Point | Public Source | How It Is Used | Limit |
|---|---|---|---|
| Temperature limits in air (Oxidizing) | Morgan Advanced Materials / Industry Guidelines | Unimpregnated carbon graphite starts to oxidize in air around 400°C to 500°C. Impregnants like antimony (up to 500°C) or resin (up to ~200°C) adjust this limit. | Continuous service up to 500°C (approx. 930°F) in air without special oxidation inhibitors. |
| Temperature limits in inert atmospheres | General carbon graphite materials guidelines | In the absence of oxygen (vacuum or inert gas), carbon graphite can operate at significantly higher temperatures without structural failure. | Can operate up to 2500°C - 3000°C, often dictated by structural integrity rather than oxidation. |
| Pressure-Velocity (PV) rating | Bearing design principles for self-lubricating materials | PV values dictate the heat generated by friction. For dry running, a typical PV limit is around 15,000 (psi × fpm) for general grades. | Actual PV limits depend on the specific grade, running clearance, heat dissipation, and shaft material. Submerged limits are higher. |
| Chemical resistance and dimensional stability | Metcar / Industrial Chemical Compatibility | Carbon-graphite is chemically inert to most caustic acids, strong alkalis, and solvents. It does not swell when exposed to water or process fluids. | Not suitable for highly oxidizing chemicals (e.g., concentrated nitric acid or fuming sulfuric acid) which can attack the carbon matrix. |
Send the drawing, speed, load, operating temperature, and any required certifications.
Complete RFQs are easier to review within 1-2 business days when drawings, graphite grade, quantity, and destination are included.
| Material Option | Best Fit Application | Watchouts & Risks |
|---|---|---|
| Carbon Graphite (Resin Impregnated) | General dry-running, high strength, up to 250°C | Not suitable for extreme high temperatures where resin degrades. |
| Carbon Graphite (Metal Impregnated) | Higher loads, improved heat dissipation, up to 500°C | Chemical compatibility depends on the impregnant (copper, antimony, babbitt). |
| Electrographite (High Purity) | Extreme temperatures (>1000°C) in inert atmospheres or vacuum | Lower mechanical strength, oxidizes rapidly above 400°C in air. |
No, they are inherently self-lubricating. A microscopic layer of graphite transfers to the shaft, preventing metal-to-metal contact and wear.
Yes, carbon graphite is chemically inert and dimensionally stable in most liquids, including water, chemicals, and fuels, making them excellent pump bearings.
Usually by shrink fitting or press fitting into a metallic housing. Care must be taken not to induce excessive hoop stress that could crack the brittle graphite.
