Which statement about MMC and LMC is true?

Which statement about MMC and LMC is true?

• A. MMC for a hole is the smallest diameter; MMC for a shaft is the largest diameter.
• B. MMC for a hole is the largest diameter; MMC for a shaft is the smallest diameter.
• C. LMC for a hole is the smallest diameter; LMC for a shaft is the largest diameter.
• D. LMC for a hole is the largest diameter; LMC for a shaft is the smallest diameter.

Answer: (B)

Max material condition (MMC) and least material condition (LMC) describe the size states of a feature of size that correspond to the most and least material remaining in the feature when manufactured. The convention used here pairs holes and shafts in opposite ways: the MMC for a hole is its largest diameter, while the MMC for a shaft is its smallest diameter. Conversely, the LMC for a hole is its smallest diameter and the LMC for a shaft is its largest diameter. This pairing matters for how tolerances (and bonus tolerance) are applied when the actual size moves toward or away from these extreme conditions. So the statement that MMC for a hole is the largest diameter and MMC for a shaft is the smallest diameter is the one that matches the standard pairing used in GD&T practice.

Max material condition (MMC) and least material condition (LMC) describe the size states of a feature of size that correspond to the most and least material remaining in the feature when manufactured. The convention used here pairs holes and shafts in opposite ways: the MMC for a hole is its largest diameter, while the MMC for a shaft is its smallest diameter. Conversely, the LMC for a hole is its smallest diameter and the LMC for a shaft is its largest diameter. This pairing matters for how tolerances (and bonus tolerance) are applied when the actual size moves toward or away from these extreme conditions. So the statement that MMC for a hole is the largest diameter and MMC for a shaft is the smallest diameter is the one that matches the standard pairing used in GD&T practice.