What is the relationship between a feature's size and a true position tolerance if MMC is not specified?

What is the relationship between a feature's size and a true position tolerance if MMC is not specified?

• A. The true position tolerance remains fixed and tied to basic position target regardless of feature size unless an MMC modifier is used
• B. The true position tolerance increases with size
• C. The tolerance depends on material
• D. The tolerance doubles

Answer: (A)

In GD&T, when no MMC modifier is specified, the true position tolerance is fixed in size and tied to the basic position target. The tolerance zone around the true position has the specified diameter, and this size does not scale with the feature’s actual size. The feature’s size only matters separately for whether the size itself satisfies its size tolerance; it does not change how much positional deviation is allowed. The only time the position tolerance would vary with size is if an MMC (or LMC) modifier is used, which makes the tolerance zone expand or contract as the feature size departs from MMC. So, without MMC, the true position tolerance remains the same regardless of the feature’s size.

In GD&T, when no MMC modifier is specified, the true position tolerance is fixed in size and tied to the basic position target. The tolerance zone around the true position has the specified diameter, and this size does not scale with the feature’s actual size. The feature’s size only matters separately for whether the size itself satisfies its size tolerance; it does not change how much positional deviation is allowed. The only time the position tolerance would vary with size is if an MMC (or LMC) modifier is used, which makes the tolerance zone expand or contract as the feature size departs from MMC. So, without MMC, the true position tolerance remains the same regardless of the feature’s size.