Millwright Level 1 Practice Exam

What is a bilateral tolerance?

1. A range of acceptable deviation in one direction

2. A range of acceptable deviation in two directions

3. A systematic error in measurement

4. A non-standardized tolerance measure

The correct answer is: A range of acceptable deviation in two directions

A bilateral tolerance refers to a specification that allows for variation in both positive and negative directions from a nominal dimension. This means that a part can deviate from the intended measurement on either side of the target value, providing a range within which the actual measurement can vary. For instance, if a part is specified to be 10 mm with a bilateral tolerance of ±1 mm, it can be acceptable anywhere between 9 mm and 11 mm. Understanding this concept is essential in manufacturing and engineering, as it allows for flexibility in production while ensuring that components remain functionally effective. A range of acceptable deviation in one direction would be classified as a unilateral tolerance, which does not account for deviations in both directions. Systematic errors in measurement and non-standardized tolerance measures do not relate specifically to the concept of bilateral tolerance. They address different aspects of measurement and quality control processes, which further distinguishes the bilateral tolerance definition.