F4:Straightness Validation: Difference between revisions
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Created page with "{{Author Credit |author=Admin }} == Summary == F4 validates straightness against the ASME logic in `1_1_0_Straightness.md` and enforces feature-type, modifier, and pattern rules. == Validation rules == * Straightness is valid only for a surface line element or a cylindrical feature of size. * Straightness cannot reference datums. * Straightness cannot be applied to a pattern. * Prohibited modifiers: projected tolerance zone, tangent plane, unequally disp..." |
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== Summary == | == Summary == | ||
F4 validates straightness against the ASME logic in | F4 validates straightness against the ASME logic in the F4 Application and enforces feature-type, modifier, and pattern rules. | ||
== Validation rules == | == Validation rules == | ||
Latest revision as of 21:12, 14 January 2026
Summary
F4 validates straightness against the ASME logic in the F4 Application and enforces feature-type, modifier, and pattern rules.
Validation rules
- Straightness is valid only for a surface line element or a cylindrical feature of size.
- Straightness cannot reference datums.
- Straightness cannot be applied to a pattern.
- Prohibited modifiers: projected tolerance zone, tangent plane, unequally disposed.
- Surface line element straightness cannot use diameter, MMC, or LMC.
- Cylindrical feature of size straightness requires the diameter modifier.
- If a linked size dimension exists, F4 compares the FCF tolerance to the size tolerance unless the cylindrical FOS exception applies.
Warnings and errors
F4 behavior
- Invalid feature type
If the FCF is applied to anything other than a surface line element or a cylindrical feature of size, F4 flags non-compliance.
F4 behavior
- Pattern not allowed
Straightness applied to a pattern is rejected.
F4 behavior
- Datum references
Any datum reference in a straightness FCF is rejected.
F4 behavior
- Missing diameter
Cylindrical feature of size straightness must include the diameter modifier.
F4 behavior
- Tolerance exceeds size tolerance
When a linked size dimension exists and a comparison is required, F4 flags non-compliance if the straightness tolerance exceeds the size tolerance.
F4 behavior
- Conditional size link
If no size dimension is linked, F4 skips the size tolerance comparison.
Examples
- Valid: straightness on a surface line element with no datums.
- Valid: straightness on a cylindrical feature of size with the diameter modifier.
- Invalid: straightness with a datum reference or applied to a pattern.