Document Type

Conference Paper

Publication Date


Publication Title

2013 ASEE Annual Conference Proceedings


1-7 (23.289.1)

Conference Name

2013 ASEE Annual Conference and Exposition, Atlanta, Georgia, June 23-26, 2013


Engineering and Engineering Technology students and professionals learning the processes and standards in computer-aided design (CAD) and computer-aided manufacturing (CAM) should learn and understand the methodology of geometric dimensioning and tolerancing (GD&T) to describe the intent and requirements for part and assembly geometries. Correct application of GD&T ensures that the part and assembly geometry defined on the drawing will have the desired form and fit (within limits) and function as intended. One learning difficulty in understanding GD&T is the concept of defining a datum axis or center plane using Maximum Material Condition (MMC). To overcome this difficulty, a new approach is presented that uses a modifier "○V " (Virtual Condition) instead of "○M " (MMC). A thorough rationalization of using "○V " in datum axis specification is discussed. The paper also provides a convenient table on how to use this modifier.


© 2013 American Society for Engineering Education, ASEE Annual Conference Proceedings, Atlanta, Georgia, June 23-26, 2013

Original Publication Citation

Lin, C. Y., Michaeli, J. G., & Tomovic, M. (2013). Clarifications of a datum axis or centerplane specifying in maximum material condition of geometric dimensioning and tolerancing. Paper presented at the 2013 ASEE Annual Conference and Exposition, Atlanta, Georgia.


0000-0002-0938-4237 (Tomovic)