GD&T: DATUMS

The following topics will be covered in this section:

Implied datum and its shortcomings

What are datum feature, datum and datum simulator

How datums are specified on a drawing

Datum precedence rule

Datum targets and its application

Axis and center-plane datums

Axis and center-plane datums with MMC modifiers

An example of datum precedence

Some special types of datum applications

Sample questions


Disclaimer: This class note has been specifically developed for classroom teaching purpose. The content of this note can be used to learn fundamental principles of GD&T. The contents of this note have been adopted from the text book "Fundamentals of Geometric Dimensioning and Tolerancing, 2nd edition, by Alex Krulikowski, Delmer Publisher. Students are advised to use this note as a supplement material in the above book.