When a hole has an MMC modifier, the actual tolerance is determined by:

• A. The diameter of the hole at nominal size.
• B. The hole's MMC.
• C. The datum target size.
• D. The projection height.

Answer: (B)

With an MMC modifier, tolerances don’t stay fixed at the nominal value; they scale with how close the feature is to its maximum material condition. For a hole, the maximum material condition is the smallest allowable diameter. So the actual tolerance used in evaluating the hole depends on the hole’s size relative to that MMC. If the hole is at its MMC, you apply the smallest tolerance; as the hole diameter increases away from MMC, the effective tolerance expands accordingly. This is why the controlling factor is the hole’s MMC. The other factors—nominal size, datum target size, or projection height—do not determine the actual tolerance when MMC is specified.