Which statement correctly describes MMC and LMC for a hole and its shaft?

Which statement correctly describes MMC and LMC for a hole and its shaft?

• A. MMC: hole at its smallest diameter; shaft is at its largest diameter.
• B. MMC: hole at its largest diameter; shaft at its smallest diameter.
• C. LMC: hole at its smallest diameter; shaft at its largest diameter.
• D. LMC: hole at its largest diameter; shaft at its smallest diameter.

Answer: (A)

Maximum Material Condition means the feature contains the most material. For a hole, the material in question is the surrounding solid around the opening, so a smaller hole leaves more material around it, giving MMC at the hole’s smallest diameter. For a shaft, the material is the shaft itself, so a larger diameter means more material in that feature, giving MMC at the shaft’s largest diameter. Hence the correct description is that the hole’s MMC is its smallest diameter and the shaft’s MMC is its largest diameter.

Maximum Material Condition means the feature contains the most material. For a hole, the material in question is the surrounding solid around the opening, so a smaller hole leaves more material around it, giving MMC at the hole’s smallest diameter. For a shaft, the material is the shaft itself, so a larger diameter means more material in that feature, giving MMC at the shaft’s largest diameter. Hence the correct description is that the hole’s MMC is its smallest diameter and the shaft’s MMC is its largest diameter.