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GD&T

GD&T Flatness: AS9102 glossary definition

GD&T flatness is a form control that limits how much a surface or derived median plane may vary from an ideal flat condition.

Updated July 3, 2026

What GD&T Flatness means

GD&T flatness is a form control that limits how much a surface or derived median plane may vary from an ideal flat condition.

Flatness can be easy to under-document because it may not use datums, but it is still a design characteristic that may require a Form 3 row when flowed on the drawing.

Use this term as a review cue: it should help connect a drawing requirement, specification, certificate, result, or approval field to the evidence a customer will inspect. If the purchase order or customer portal uses stricter wording, follow that controlled source instead of this glossary entry.

Where it appears in AS9102

On Form 3, flatness belongs in the requirement field with its tolerance and feature context. The result should show the measured or accepted condition and supporting evidence.

In an Articul review, this term is treated as part of the traceability path from source drawing or flowed requirement to form field, evidence, validation issue, and final approval. Use the AS9102 standard text as the controlled source, and use this glossary to clarify reviewer-facing meaning before export. When the term is ambiguous, keep the reviewer note close to the row or field it affects.

Review notes

  • Check whether the flatness applies to a surface, a feature of size, or another controlled element, and make sure the inspection method matches the requirement.
  • Do not combine flatness with a nearby size result unless the evidence clearly verifies both requirements.
  • Keep wording, units, identifiers, and attachment names consistent across the drawing, Forms 1-3, evidence files, and any customer portal submission.
AS9102 Forms 1-3 guideField-by-field hub for the complete FAIR packageHow to fill out Form 3Characteristic requirement, result, and nonconformance reviewAS9102 Form 3 templateCharacteristic accountability workbook and completed exampleBallooned drawing examplesSample prints paired with downloadable Form 3 rows
RequirementA requirement is the design or flowed condition that a Form 3 row must verify, such as a dimension, tolerance, note, GD&T control, finish, material callout, or specification reference.Inspection ResultAn inspection result is the evidence value or acceptance statement entered on Form 3 to show how a characteristic was verified against its requirement.GD&T True PositionGD&T true position is a geometric control that defines the allowed location variation of a feature relative to specified datums and tolerance conditions.

FAQ

What does GD&T Flatness mean in an AS9102 FAIR?

GD&T flatness is a form control that limits how much a surface or derived median plane may vary from an ideal flat condition. Check whether the flatness applies to a surface, a feature of size, or another controlled element, and make sure the inspection method matches the requirement.

Source notes

This Articul glossary entry is based on the public AS9102 field matrix used in product validation and on the internal review patterns linked from the related guides. It is not a replacement for purchased AS9102 text, customer requirements, or purchase order flowdowns.

Changelog

July 3, 2026: Published the first GD&T Flatness glossary entry with DefinedTerm, FAQPage, and BreadcrumbList schema plus links to related AS9102 guides and terms.

Keep the FAIR review tied to the print

Articul pre-fills Forms 1-3 from the print and routes anything uncertain to you, including drawing notes and title-block fields, while preserving source traceability for review.

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