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F4 Wiki

A trusted GD&T reference with F4 validation behavior, reviewed and published by moderators.

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• Forum

How to use this wiki

• The public view shows approved revisions only.
• Each GD&T page links to its matching F4 validation page.
• Use the sidebar or search to find topics quickly.

Featured pages

• GDT:Straightness
• GDT:Flatness
• GDT:Position
• GDT:Profile of a Surface
• F4:Position Validation

Contribute

• Contributor guide
• License
• Review queue