GD&T Symbol Guide
Free State Symbol
Marks a dimension or tolerance that must be evaluated while a non-rigid part is unrestrained.
Definition
The free state symbol means the associated requirement is checked without external forces except gravity.
It is useful on flexible sheet metal, rubber, plastic, and other parts that can change shape when restrained.
Application
Use it to exempt a specific feature from a drawing-wide restrained condition note.
Place it after the tolerance value in the feature control frame or with the applicable dimension.
Free State Symbol Drawing Use
Free State Symbol is read with the adjacent dimension, note, or feature control frame so inspection uses the intended feature definition.
3D Tolerance Zone
This modifier changes how a related dimension, note, or feature control frame is interpreted.
Inspection Method
Read the symbol with the attached dimension, note, or feature control frame before evaluating the feature.
Verify the controlled feature using the drawing's stated limits, datum setup, and any special notes tied to the symbol.
Worked Read: Free State Symbol
A drawing includes the Free State Symbol symbol with a related feature requirement.
Identify
F
Recognize the Free State Symbol symbol and the feature it modifies.
Read
Adjacent value
Use the attached dimension, note, or frame cells as the controlling requirement.
Inspect
Per drawing
Measure the named feature using the specified interpretation rather than assuming a generic size check.
Free State Symbol clarifies how the feature is defined so the drawing and inspection method stay aligned.
Comparison Table
| Item | Controls | Typical Placement |
|---|---|---|
| Free State Symbol | Requirement interpretation | Next to a dimension, note, or frame |
| GD&T control | Geometric variation | Feature control frame |
| Datum reference | Measurement setup | Datum feature or frame cell |
Notes
This page is part of the drawing-symbol reference set rather than a standalone geometric tolerance category.
When the symbol modifies a feature control frame, read it together with the tolerance value and datum references.