Inch Tolerances
Definitions
Limits: The limits are the maximum and minimum size that the part is allowed to be.
Basic Size: The basic size is the size from which the limits are calculated. It is common for both the hole and the shaft and is usually the closest fraction.
Tolerance: The tolerance is the total amount a specific dimension is permitted to vary.
Maximum Material Condition (MMC): The MMC is the size of the part when it consists of the most material.
Least Material Condition (LMC): The LMC is the size of the part when it consists of the least material.
Maximum Clearance: The maximum amount of space that can exist between the hole and the shaft.
Max. Clearance = LMChole – LMCshaft
Minimum Clearance (Allowance): The minimum amount of space that can exist between the hole and the shaft.
Min. Clearance = MMChole – MMCshaft