What is an "independent" tolerance?

• A. A tolerance that is affected by external conditions
• B. A tolerance that is not influenced by other features
• C. A general tolerance that applies to all parts
• D. A tolerance that only applies to specific dimensions

Answer: (B)

An "independent" tolerance refers to a tolerance that is not influenced by other features in the part or assembly. This means that the dimension to which it refers can vary without causing any impact on the other tolerances or features in the design. In scenarios where several features might interrelate, independent tolerances allow for more design freedom, as they ensure that adjustments to one dimension do not compromise the integrity or functionality of other features.

For example, if two features are dimensioned with independent tolerances, modifying the size or position of one feature would not necessitate adjustments to the other, simplifying the manufacturing and inspection processes. This is particularly critical in complex assemblies where multiple parts interact, as it aids in maintaining design integrity while simplifying fabrication.

The other options describe concepts that don't align with the definition of an independent tolerance. For instance, a tolerance affected by external conditions suggests reliance on factors outside the part's dimensions, while general tolerances and tolerances specifically applicable to individual dimensions imply a level of dependency that contradicts the essence of independence in tolerancing.