For those of you who actively use GD&T on a daily basis, you should be aware of the certification process for GD&T Professionals.
The American Society of Mechanical Engineers (ASME) has established a credential for GD&T proficiency, called GDTP, which stands for Geometric Dimensioning and Tolerancing Professional.
It is a testing process that measures your ability to interpret and apply tolerances correctly.
There are actually two certification levels: the Technologist Level, which measures your ability to read GD&T; and the Senior Level, which tests not only interpretation, but also the application of GD&T to a design. One does not necessarily need to become a Technologist first; some people go right for the Senior Level, although they are required to document at least five years of experience in GD&T (and they have a more difficult test!).
If you decide to pursue either level, be aware that the questions on the test can be taken from any section of the Y14.5 standard. Each chapter has a “weight” that determines the number of questions from the chapter that appear on the test. This means that there is more than just GD&T; you need to be familiar with the nuances of traditional tolerancing as well as the many definitions contained in that standard. Some questions representative of the Technologist Level:
Sample question #1:
A dimension “not to scale” is symbolized by:
a. placing the number in parentheses
b. placing a line under the number
c. including NTS after the number
d. italicizing the number
Sample question #2:
If a datum feature of size is applied RFS, a datum displacement is:
a. not allowed
b. allowed at MMC
c. allowed at LMC
d. allowed at the resultant condition
Sample question #3:
Which of the following datum feature symbols is incorrect?
The GDTP process is not for everybody, but if it’s something that might interest you, contact us for some guidance or you may visit ASME’s website for more detail: