What is a pattern of holes tolerance called?

What is a pattern of holes tolerance called?

• A. Pattern position tolerance.
• B. Cylindrical runout tolerance.
• C. Datum reference tolerance.
• D. True profile tolerance.

Answer: (A)

When a group of holes is arranged in a pattern, you control their overall location with a pattern position tolerance. This GD&T callout applies a true-position style tolerance to the entire pattern, so every hole in that pattern must lie within the specified tolerance zone relative to the defined datums. It ensures the pattern is placed where it’s supposed to be, such as on a bolt circle or grid, instead of just checking each hole individually. The other concepts don’t fit this situation: cylindrical runout relates to how a surface or feature runs as the part rotates; datum reference tolerance isn’t a standard term for this purpose; true profile governs the shape of a feature’s edge rather than the location of multiple features in a pattern.

When a group of holes is arranged in a pattern, you control their overall location with a pattern position tolerance. This GD&T callout applies a true-position style tolerance to the entire pattern, so every hole in that pattern must lie within the specified tolerance zone relative to the defined datums. It ensures the pattern is placed where it’s supposed to be, such as on a bolt circle or grid, instead of just checking each hole individually.

The other concepts don’t fit this situation: cylindrical runout relates to how a surface or feature runs as the part rotates; datum reference tolerance isn’t a standard term for this purpose; true profile governs the shape of a feature’s edge rather than the location of multiple features in a pattern.