What is LMC (Least Material Condition) for a hole and for a shaft?

What is LMC (Least Material Condition) for a hole and for a shaft?

• A. For a hole, LMC is the largest diameter; for a shaft, LMC is the smallest diameter.
• B. For a hole, LMC is the smallest diameter; for a shaft, LMC is the largest diameter.
• C. LMC applies only to shafts.
• D. LMC is unrelated to holes.

Answer: (A)

Least material condition means the state where the feature has the least material remaining. For a hole, having the hole at its largest acceptable diameter leaves the least material around it, so the LMC for a hole is the largest diameter. For a shaft, having the shaft at its smallest acceptable diameter leaves the least material along the cylindrical section, so the LMC for a shaft is the smallest diameter. That matches the described option. (As a reference, maximum material condition would be the opposite: smallest hole and largest shaft.)

Least material condition means the state where the feature has the least material remaining. For a hole, having the hole at its largest acceptable diameter leaves the least material around it, so the LMC for a hole is the largest diameter. For a shaft, having the shaft at its smallest acceptable diameter leaves the least material along the cylindrical section, so the LMC for a shaft is the smallest diameter. That matches the described option. (As a reference, maximum material condition would be the opposite: smallest hole and largest shaft.)