GDT:Position: Difference between revisions
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|modifiers=Diameter for cylindrical FOS; MMC, LMC, RFS; ST where allowed | |modifiers=Diameter for cylindrical FOS; MMC, LMC, RFS; ST where allowed | ||
|tolerance_zone=Cylindrical zone or two parallel planes located by basic dimensions | |tolerance_zone=Cylindrical zone or two parallel planes located by basic dimensions | ||
|image= | |image=GDT-Position.svg | ||
|mistakes=Missing basic dimensions; missing datum references; missing diameter on cylindrical FOS | |mistakes=Missing basic dimensions; missing datum references; missing diameter on cylindrical FOS | ||
|related=[[F4:Position Validation]] | |related=[[F4:Position Validation]] | ||
Latest revision as of 19:30, 15 January 2026
| Symbol | Position |
|---|---|
| Type | Location |
| Category | Location |
| Standard | ASME Y14.5 |
| Author | Admin |
| Datums | Primary datum required (typical) |
| Modifiers | Diameter for cylindrical FOS; MMC, LMC, RFS; ST where allowed |
| Tolerance zone | Cylindrical zone or two parallel planes located by basic dimensions |
| Image | GDT-Position.svg |
| Common mistakes | Missing basic dimensions; missing datum references; missing diameter on cylindrical FOS |
| Related | F4:Position Validation |
Summary
Position controls the location of a feature relative to datums using basic dimensions.
Definition
The tolerance zone is located by basic dimensions relative to the datum reference frame. For cylindrical features, the zone is typically a cylinder; for planar features of size, the zone is two parallel planes.
When to use it
Use position to control hole patterns, slots, or planar features of size that must be located relative to datums.
Examples
Example: Hole position relative to datums
Position applied to a hole with basic dimensions and datum references.
Example: Planar feature of size position
Position applied to a slot with basic dimensions and datum A reference.
Common mistakes
- Missing basic dimensions for true position.
- Missing datum references.
- Omitting the diameter modifier for cylindrical features of size.