GDT:Position Composite FCF
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| Symbol | Position Composite FCF |
|---|---|
| Type | Location |
| Category | Composite FCF |
| Standard | ASME Y14.5 |
| Author | Admin |
| Datums | Required; lower segments must be ordered subsets |
| Modifiers | Material condition modifiers must be consistent across segments |
| Tolerance zone | Multiple segments with decreasing tolerance values |
| Image | GDT-Position-Composite-FCF.svg |
| Common mistakes | Using non-position/profile symbols; invalid datum subsets; inconsistent modifiers; tolerance values not decreasing |
| Related | F4:Position Composite Validation |
Summary
Position composite feature control frames control a pattern with multiple tolerance zones in stacked segments.
Definition
A composite FCF contains two or more segments that refine location requirements. Lower segments are more restrictive and typically reference fewer datums.
When to use it
Use position composite FCFs to control a pattern with both overall location and finer pattern-to-pattern control.
Examples
Example: Composite position on a hole pattern
Two-segment composite position controlling overall and local pattern variation.
Common mistakes
- Using non-position/profile symbols in composite segments.
- Datum references not in ordered subset hierarchy.
- Modifiers not consistent across segments.
- Tolerance values that do not decrease in lower segments.