Revision as of 22:16, 14 January 2026

F4 Wiki

The public, stable reference for GD&T and how the F4 Application interprets it.
Each topic pairs standard GD&T guidance with F4 validation behavior so you can move from definition to decision quickly.

GD&T Reference
Standard definitions, symbols, and usage guidance.

F4 Behavior
Rules, checks, and decisions used by the F4 validator.

Glossary and Examples
Short definitions and worked applications.

Browse by category

- straightness, flatness, circularity, cylindricity.
- parallelism, perpendicularity, angularity.
- position, composite, MSS, concentricity, symmetry.
- line, surface, composite, MSS.
- circular and total runout.
and for supporting rules.

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

About F4

F4 is an engineering platform focused on GD&T interpretation and compliance checks. Use this wiki alongside the official docs and downloads.

Contribute

@@ Line 2: / Line 2: @@
 = F4 Wiki =
-A trusted GD&T reference with F4 validation behavior, reviewed and published by moderators.
+<div style="background: var(--f4-bg-panel); border: 1px solid var(--f4-border); border-radius: 12px; padding: 1.2em; margin-bottom: 1.2em;">
+''The public, stable reference for GD&T and how the F4 Application interprets it.''<br>
+Each topic pairs standard GD&T guidance with F4 validation behavior so you can move from definition to decision quickly.
+</div>
-This wiki is the public, stable reference for how GD&T concepts are defined and how the F4 Application interprets and validates them.
+{| style="width: 100%; border-collapse: separate; border-spacing: 12px;"
-Every page links standard guidance to F4-specific behavior so engineers can move from definition to decision quickly.
+|-
+| style="vertical-align: top; width: 33%;" |
+<div style="background: var(--f4-bg-panel); border: 1px solid var(--f4-border); border-radius: 10px; padding: 0.9em;">
+'''GD&T Reference'''<br>
+Standard definitions, symbols, and usage guidance.
+* [[Category:GDT Reference|Browse GD&T Reference]]
+</div>
+| style="vertical-align: top; width: 33%;" |
+<div style="background: var(--f4-bg-panel); border: 1px solid var(--f4-border); border-radius: 10px; padding: 0.9em;">
+'''F4 Behavior'''<br>
+Rules, checks, and decisions used by the F4 validator.
+* [[Category:F4 Behavior|Browse F4 Behavior]]
+</div>
+| style="vertical-align: top; width: 33%;" |
+<div style="background: var(--f4-bg-panel); border: 1px solid var(--f4-border); border-radius: 10px; padding: 0.9em;">
+'''Glossary and Examples'''<br>
+Short definitions and worked applications.
+* [[Category:Glossary|Glossary]]
+* [[Category:Examples|Examples]]
+</div>
+|}
-== Quick start ==
+== Browse by category ==
-* [[Category:GDT Reference|GD&T Reference]] for standard definitions and examples.
+* [[Category:Form|Form]] - straightness, flatness, circularity, cylindricity.
-* [[Category:F4 Behavior|F4 Behavior]] for validation rules, warnings, and errors.
+* [[Category:Orientation|Orientation]] - parallelism, perpendicularity, angularity.
-* [[Category:Glossary|Glossary]] for short definitions.
+* [[Category:Location|Location]] - position, composite, MSS, concentricity, symmetry.
-* [[Category:Examples|Examples]] for worked applications.
+* [[Category:Profile|Profile]] - line, surface, composite, MSS.
-* [[Forum:Start|Community forum]] for discussions and questions.
+* [[Category:Runout|Runout]] - circular and total runout.
+* [[Category:Modifiers|Modifiers]] and [[Category:Datums|Datums]] for supporting rules.
+== 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 ==
@@ Line 18: / Line 49: @@
 * Each GD&T page links to its matching F4 validation page.
 * Use the sidebar or search to find topics quickly.
-* When an item requires interpretation, the F4 page calls out the decision and how it affects compliance.
+* When a rule needs interpretation, the F4 page calls out the decision and its impact.
+== Community ==
+* [[Forum:Start|Community forum]]
+* [[Special:UserBoard|Messages]]
 == About F4 ==
@@ Line 27: / Line 62: @@
 * [https://docs.f4.dev/ Documentation]
 * [https://download.f4.dev/ Downloads]
-== Featured pages ==
-* [[GDT:Straightness]]
-* [[GDT:Flatness]]
-* [[GDT:Position]]
-* [[GDT:Profile of a Surface]]
-* [[F4:Position Validation]]
 == Contribute ==
@@ Line 39: / Line 67: @@
 * [[F4_Wiki:License|License]]
 * [[Special:ApprovedRevs|Review queue]]
-* [[Special:UserBoard|Messages]]