In a hole pattern, which tolerance constrains the centers?

In a hole pattern, which tolerance constrains the centers?

• A. Datum feature tolerance.
• B. Profile of a surface tolerance.
• C. Pattern position tolerance.
• D. Total runout tolerance.

Answer: (C)

When you want to control where the centers of a hole pattern sit, you use the pattern position tolerance. This tolerance defines the true position of each hole center relative to the datum reference frame, typically with a cylindrical tolerance zone around the ideal center line for each hole in the pattern. It ensures the entire pattern is located within the specified limits so the holes will align as intended with mating parts. The other tolerances address different aspects: datum feature tolerance governs how the datum surfaces themselves must be manufactured and located, profile of a surface constrains the shape of a surface, and total runout controls the cumulative angular deviation of a feature as the part is rotated. None of those specifically constrain the centers of a hole pattern like pattern position does.

When you want to control where the centers of a hole pattern sit, you use the pattern position tolerance. This tolerance defines the true position of each hole center relative to the datum reference frame, typically with a cylindrical tolerance zone around the ideal center line for each hole in the pattern. It ensures the entire pattern is located within the specified limits so the holes will align as intended with mating parts.

The other tolerances address different aspects: datum feature tolerance governs how the datum surfaces themselves must be manufactured and located, profile of a surface constrains the shape of a surface, and total runout controls the cumulative angular deviation of a feature as the part is rotated. None of those specifically constrain the centers of a hole pattern like pattern position does.