Fit and Clearance Calculator

When to use this CAD helper

• Use it before selecting a bearing, bushing, sliding shaft, press fit, or supplier tolerance note.
• Use it when user-supplied deviations are available but full standards table lookup is outside scope.

How to use

1. Enter only the small dimensions, drawing notes, or checklist selections needed for this browser-local CAD helper.
2. Click the exact action button; default values, typing, URL-prefilled values, and worked examples do not generate output automatically.
3. Review warnings, assumptions, result visual, copy text, and downloads before using the output in a CAD, drawing, or manufacturing workflow.
4. Verify generated values and text against your organization standards, supplier requirements, and qualified engineering judgment.

Input guide

Hole nominal and deviations

Nominal size plus upper and lower deviations.

Shaft nominal and deviations

Nominal size plus upper and lower deviations.

Application type

Sliding, clearance, transition, interference, bearing/press-fit guidance, or generic context.

Notation

Output interpretation

• Limit sizes, clearance range, fit classification, warnings, visual tolerance bands, and text download.

Supported CAD use cases

• hole/shaft limit calculations
• clearance fit
• transition fit
• interference fit

Unsupported patterns

• automatic ISO fit selection
• press-force prediction
• thermal assembly simulation

How to interpret the output

• If minimum clearance is positive, the fit is clearance.
• If maximum clearance is negative, the fit is interference.
• Otherwise the fit is transition.

Practical CAD workflow guidance

• Check finish, lubrication, roundness, temperature, and assembly method in addition to numeric clearance.

Worked examples

Assumptions

• Inputs are user-supplied planning values and are not read from CAD files.
• Units, tolerances, drawing notes, and release decisions remain the user's responsibility.
• Generated text, tables, and checklists are editable planning aids, not controlled engineering approvals.
• All deviations are signed values in the selected unit.

Practical guidance

• Use tolerance stack-up for multi-part assemblies before checking the final fit.

Common mistakes

• Entering lower deviations as positive when they are below nominal.
• Assuming fit classification is enough for bearing or press-fit design.

Limitations

• No official fit table lookup, material expansion, contact stress, or assembly-force calculation is included.
• The tool does not open, parse, upload, validate, or execute CAD files, STL files, drawings, macros, or proprietary model data.
• The tool does not replace CAD software, GD&T standards, supplier review, validated manufacturing software, or qualified engineering judgment.
• ScholarTool CAD helpers provide general engineering calculation, checklist, and documentation support. ScholarTool is not affiliated with or endorsed by any CAD software vendor. Always verify drawing, tolerance, thread, material, and manufacturing requirements against your organization's standards and supplier requirements.

Related workflow links