locus conditions

The envelope established by the combined effects of tolerance of size or form and location. Two such conditions exist.

a) outer locus (OL)

1) For a male feature, the worst-case (largest) boundary or envelope of the outer surface of the feature as it moves around the tolerance zone of position.

OL = MMC + positive tolerance

2) For a female feature, the worst-case (largest) boundary or locus formed outside of the surface of the feature as it moves around the tolerance zone of position.

OL = LMC + positive tolerance

where MMC is maximum material condition and LMC is least material condition.

b) inner locus (IL)

1) For a male feature, the worst-case (smallest) boundary or locus formed inside the surface of the feature as it moves around the tolerance zone of position.

IL = LMC - positive tolerance

2) For a female feature, the worst-case (smallest) boundary or envelope of the inner surface of the feature as it moves around the tolerance zone of position.

IL = MMC - positive tolerance

References