Estimate differential thermal growth from your selected material data, then use the result to prepare a clearance review. We manufacture custom carbon graphite bearings for application- specific operating conditions.
Request a drawing-based engineering reviewPublished September 24, 2026 · Last reviewed October 10, 2026
Check both supplier CTE values, then estimate. The result will show differential diameter change only; it will not size the bearing clearance.
Compare the shaft and selected bearing grade using supplier CTE values. Published carbon grades do not share one universal expansion value.
Temperature limits depend on the exact impregnation and product grade. Treat catalog limits as grade-specific data, not family-wide rules.
Confirm the shaft material, hardness, finish, load, and speed with the bearing manufacturer for the selected grade.
The estimate compares shaft and bore diameter changes. It assumes both parts experience the same uniform temperature change and use constant, supplier-provided coefficients.
ΔD = (Dshaft × αshaft − Dbore × αbore) × 10⁻⁶ × ΔT
Dshaft and Dbore are the cold shaft and bore diameters in mm, α values are entered in 10⁻⁶/°C, and ΔT is operating minus assembly temperature in °C. A positive result reduces available diametral clearance in this simple model; a negative result increases it.
This does not set the cold bore, running clearance, fit, tolerance, or grade. It omits temperature gradients, housing restraint, pressure, speed, load, wear, fluid effects, and installation conditions. Use the actual grade data sheet and request a complete operating-fit review before machining.
Toyo Tanso's published mechanical-carbon table shows different CTE values across listed grades and labels them as typical, not guaranteed [S2]. Use that data as a reason to obtain the specific grade value, not as a substitute for it.
These are examples from named manufacturer literature, not universal ratings for resin, PTFE, or antimony grades.
| Grade family | Published reference | What to confirm before specification |
|---|---|---|
| Phenolic-resin impregnated | Mersen lists 200°C maximum operating temperature for its JP phenolic option. [S3] | Confirm the exact resin grade, fluid chemistry/concentration, pressure, and temperature with the supplier. |
| PTFE-impregnated | Mersen lists 250°C maximum operating temperature for its JP PTFE option. [S3] | Confirm the exact grade and compatibility with the process fluid and operating cycle. |
| Antimony-impregnated | Mersen lists 450°C maximum operating temperature for its JP antimony option. [S3] | Confirm the exact manufacturer grade, atmosphere, load, speed, and counterface requirements. |
| Base carbon-graphite | A bearing manufacturer notes that dry-running suitability depends on the application and selected grade. [S1] | Request grade-specific speed/load limits, wear guidance, temperature data, and clearance review. |
Share the application context needed to review grade, fit, tolerances, and manufacturability. The calculator above does not replace these inputs.
A bearing manufacturer describes grade selection as application-dependent, with operating temperature, dry running, and load among the factors; it also distinguishes dry and wet running clearance guidance.
The manufacturer publishes grade-specific thermal-expansion values and states that the listed figures are typical and not guaranteed.
The manufacturer lists temperature ratings for its specific impregnation options, including phenolic resin, PTFE, and antimony; these are examples for the named product family, not universal limits.
References checked October 10, 2026. Manufacturer values and recommendations apply only to the named products and conditions.
Prepared by Custom Graphite Parts.
The shaft and bearing bore can grow by different amounts as temperature changes. Use the selected shaft and bearing-grade data, actual component temperatures, and specified fit to review operating clearance; graphite CTE is not one universal value.
Some carbon-graphite grades can run dry in suitable conditions, but dry-running capability depends on grade, load, speed, temperature, atmosphere, and shaft pairing. Ask the manufacturer to confirm the intended duty for the exact grade.
No. It estimates only the difference between shaft and bore diameter growth for the inputs supplied. It does not include base clearance, fits, tolerances, speed/load effects, or temperature gradients.
No. The values shown are examples published for specific Mersen product options. Confirm the current rating for the exact supplier grade and your atmosphere, pressure, fluid, and duty cycle.
Send the latest drawing, shaft and bore dimensions, operating and assembly temperatures, speed, load, pressure, process fluid and concentration, wet/dry condition, atmosphere, and counterface material/finish.
Lead time depends on grade availability, impregnation, geometry, drawing approval, and inspection requirements. Request a schedule with the quote so it reflects the current specification and production plan.
Send your drawing, operating temperatures, speed, load, pressure, process medium, and shaft details. Request a grade-specific review of the operating fit, material limits, and manufacturing tolerances before releasing dimensions.
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