How Shaft and Hole Fits Work
When this applies
Use this guide when drawings show letters and grades but the assembly intent still feels ambiguous in review meetings.
Tool to use
Browser-based preliminary check for Shaft Hole Fit Calculator — fast estimates, not code or stamped design output.
Open Shaft Hole Fit Calculator →Steps
- 1Determine whether the interface needs sliding, location, or press behavior.
- 2Map nominal size to standard tolerance grades for shaft and hole.
- 3Compute worst-case clearance or interference from limits.
- 4Compare against assembly process constraints (press force, thermal shrink, lubrication).
- 5Coordinate with inspection on measurable features and datum scheme.
Examples
- Sliding gear on shaft vs interference bearing seat.
- Location pin that must not seize during thermal expansion.
What to avoid
- Ignoring surface finish and deformation in tight interference fits.
- Mixing ISO and imperial tolerance systems without conversion discipline.
- Assuming nominal always assembles when limits overlap badly in worst case.
Related tools
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Browse all task guides or see the full list on the Engineering hub.
FAQ
Does this replace GD&T?
No. It supports fit sizing, not full datum referencing.
Temperature effects?
Add thermal expansion checks when service temperature spans are wide.