GDT:Profile Composite FCF
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| Symbol | Profile Composite FCF |
|---|---|
| Type | Profile |
| Category | Composite FCF |
| Standard | ASME Y14.5 |
| Author | Admin |
| Datums | Optional; when used, lower segments must be ordered subsets |
| Modifiers | Dynamic profile, non-uniform, tangent, unequal, free state, ST where allowed |
| Tolerance zone | Multiple profile zones with decreasing tolerances |
| Image | |
| Common mistakes | Using non-profile symbols; missing true profile location; invalid datum subsets; disallowed modifiers; tolerance values not decreasing |
| Related | F4:Profile Composite Validation |
Summary
Profile composite feature control frames refine profile control across multiple segments.
Definition
A profile composite FCF contains two to five stacked segments. Each lower segment refines the tolerance zone, typically with a smaller tolerance and a reduced datum reference set. The composite applies to a true profile or true profile pattern located by basic or toleranced dimensions.
When to use it
Use a profile composite FCF when you need both an overall profile requirement and tighter refinement on the same surface or pattern.
Examples
Example: Composite profile on a contoured surface
A two-segment composite profile with a smaller tolerance in the lower segment and a reduced datum reference.
Common mistakes
- Using non-profile symbols in composite segments.
- Not locating the true profile with basic or toleranced dimensions.
- Datum references that are not ordered subsets of the segment above.
- Using prohibited modifiers such as diameter, MMC, or LMC.
- Tolerance values that do not decrease in lower segments.