F4 Wiki

<htmltag tagname="div" style="background: var(--f4-bg-panel); border: 1px solid var(--f4-border); border-radius: 12px; padding: 1.2em; margin-bottom: 1.2em;"> <htmltag tagname="div" style="display: flex; gap: 16px; align-items: center; flex-wrap: wrap;"> <htmltag tagname="div" style="flex: 0 0 auto;"> <htmltag tagname="img" src="/resources/assets/logo-white.svg" alt="F4" width="56" height="56" loading="lazy"></htmltag> </htmltag> <htmltag tagname="div" style="flex: 1 1 320px;"> <htmltag tagname="div" style="font-size: 1.2em; font-weight: 600;">The public, stable reference for GD&T and how the F4 Application interprets it.</htmltag> <htmltag tagname="div" style="margin-top: 0.4em; color: var(--f4-text-muted);">Each topic pairs standard GD&T guidance with F4 validation behavior so you can move from definition to decision quickly.</htmltag> </htmltag> </htmltag> <htmltag tagname="div" style="margin-top: 0.9em; display: flex; gap: 8px; flex-wrap: wrap;"> <htmltag tagname="a" href="https://f4.dev/" style="display: inline-block; padding: 6px 10px; border-radius: 8px; background: var(--f4-bg-surface); border: 1px solid var(--f4-border); color: var(--f4-text); text-decoration: none;">F4 website</htmltag> <htmltag tagname="a" href="https://docs.f4.dev/" style="display: inline-block; padding: 6px 10px; border-radius: 8px; background: var(--f4-bg-surface); border: 1px solid var(--f4-border); color: var(--f4-text); text-decoration: none;">Documentation</htmltag> <htmltag tagname="a" href="https://download.f4.dev/" style="display: inline-block; padding: 6px 10px; border-radius: 8px; background: var(--f4-bg-surface); border: 1px solid var(--f4-border); color: var(--f4-text); text-decoration: none;">Downloads</htmltag> </htmltag> </htmltag>

<htmltag tagname="a" href="/index.php/Category:GDT_Reference" style="display: block; background: var(--f4-bg-panel); border: 1px solid var(--f4-border); border-radius: 10px; padding: 0.9em; text-decoration: none; color: var(--f4-text);"> <htmltag tagname="div" style="font-weight: 600;">GD&T Reference</htmltag> <htmltag tagname="div" style="margin-top: 0.4em; color: var(--f4-text-muted);">Standard definitions, symbols, and usage guidance.</htmltag> </htmltag>

<htmltag tagname="a" href="/index.php/Category:F4_Behavior" style="display: block; background: var(--f4-bg-panel); border: 1px solid var(--f4-border); border-radius: 10px; padding: 0.9em; text-decoration: none; color: var(--f4-text);"> <htmltag tagname="div" style="font-weight: 600;">F4 Behavior</htmltag> <htmltag tagname="div" style="margin-top: 0.4em; color: var(--f4-text-muted);">Rules, checks, and decisions used by the F4 validator.</htmltag> </htmltag>

<htmltag tagname="a" href="/index.php/Category:Glossary" style="display: block; background: var(--f4-bg-panel); border: 1px solid var(--f4-border); border-radius: 10px; padding: 0.9em; text-decoration: none; color: var(--f4-text);"> <htmltag tagname="div" style="font-weight: 600;">Glossary and Examples</htmltag> <htmltag tagname="div" style="margin-top: 0.4em; color: var(--f4-text-muted);">Short definitions and worked applications.</htmltag> <htmltag tagname="div" style="margin-top: 0.6em; color: var(--f4-accent);">Browse glossary and examples</htmltag> </htmltag>

Browse by category

<htmltag tagname="a" href="/index.php/Category:Form" style="display: block; background: var(--f4-bg-panel); border: 1px solid var(--f4-border); border-radius: 10px; padding: 0.9em; text-decoration: none; color: var(--f4-text);"> <htmltag tagname="div" style="font-weight: 600;">Form</htmltag> <htmltag tagname="div" style="margin-top: 0.4em; color: var(--f4-text-muted);">Straightness, flatness, circularity, cylindricity.</htmltag> </htmltag>	<htmltag tagname="a" href="/index.php/Category:Orientation" style="display: block; background: var(--f4-bg-panel); border: 1px solid var(--f4-border); border-radius: 10px; padding: 0.9em; text-decoration: none; color: var(--f4-text);"> <htmltag tagname="div" style="font-weight: 600;">Orientation</htmltag> <htmltag tagname="div" style="margin-top: 0.4em; color: var(--f4-text-muted);">Parallelism, perpendicularity, angularity.</htmltag> </htmltag>
<htmltag tagname="a" href="/index.php/Category:Location" style="display: block; background: var(--f4-bg-panel); border: 1px solid var(--f4-border); border-radius: 10px; padding: 0.9em; text-decoration: none; color: var(--f4-text);"> <htmltag tagname="div" style="font-weight: 600;">Location</htmltag> <htmltag tagname="div" style="margin-top: 0.4em; color: var(--f4-text-muted);">Position, composite, MSS, concentricity, symmetry.</htmltag> </htmltag>	<htmltag tagname="a" href="/index.php/Category:Profile" style="display: block; background: var(--f4-bg-panel); border: 1px solid var(--f4-border); border-radius: 10px; padding: 0.9em; text-decoration: none; color: var(--f4-text);"> <htmltag tagname="div" style="font-weight: 600;">Profile</htmltag> <htmltag tagname="div" style="margin-top: 0.4em; color: var(--f4-text-muted);">Line, surface, composite, MSS.</htmltag> </htmltag>
<htmltag tagname="a" href="/index.php/Category:Runout" style="display: block; background: var(--f4-bg-panel); border: 1px solid var(--f4-border); border-radius: 10px; padding: 0.9em; text-decoration: none; color: var(--f4-text);"> <htmltag tagname="div" style="font-weight: 600;">Runout</htmltag> <htmltag tagname="div" style="margin-top: 0.4em; color: var(--f4-text-muted);">Circular and total runout.</htmltag> </htmltag>	<htmltag tagname="div" style="background: var(--f4-bg-panel); border: 1px solid var(--f4-border); border-radius: 10px; padding: 0.9em;"> <htmltag tagname="div" style="font-weight: 600;">Supporting rules</htmltag> <htmltag tagname="div" style="margin-top: 0.4em;"> and .</htmltag> </htmltag>

Featured pages

GDT:Straightness - basic line element form control.
GDT:Flatness - planar form control.
GDT:Position - primary location control for features of size.
GDT:Profile of a Surface - shape and location combined.
F4:Position Validation - how F4 checks position.

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.
When a rule needs interpretation, the F4 page calls out the decision and its impact.

Community

<htmltag tagname="a" href="/index.php/Forum:Start" style="display: block; background: var(--f4-bg-panel); border: 1px solid var(--f4-border); border-radius: 10px; padding: 0.9em; text-decoration: none; color: var(--f4-text);"> <htmltag tagname="div" style="font-weight: 600;">Community forum</htmltag> <htmltag tagname="div" style="margin-top: 0.4em; color: var(--f4-text-muted);">Announcements, questions, feature requests, and showcases.</htmltag> </htmltag>

<htmltag tagname="a" href="/index.php/Special:UserBoard" style="display: block; background: var(--f4-bg-panel); border: 1px solid var(--f4-border); border-radius: 10px; padding: 0.9em; text-decoration: none; color: var(--f4-text);"> <htmltag tagname="div" style="font-weight: 600;">Messages</htmltag> <htmltag tagname="div" style="margin-top: 0.4em; color: var(--f4-text-muted);">Direct messages between contributors.</htmltag> </htmltag>

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