Quick Reference: http://www.gdandtbasics.com/gdt-symbols/

Classes:

https://www.regonline.com/builder/site/default.aspx?EventID=1166827

Indicate Technologies in Sunnyvale

Thoughts:

Mason:

In my experience, GDT is definitely a superior way of dimensioning parts to really control things properly. BUT it's hard enough for engineers to really understand, much less the people doing the inspection. So as much as I want to use it, I keep falling back to mostly old fashioned dimensions that people can measure with calipers and simple CMM measurements.

Tom:

+1 What Mason said. It's great stuff, but in practice I use it only when absolutely necessary - and more often that not I end up writing a long note callout describing what I want. A lot of manufacturers don't use GD&T and are only confused by the nomenclature.

Andrew:

I would tend to agree with Mason, although I am less inclined to give up on GD&T if a shop isn't familiar. In my experience if the dimensions are truly CTF, and especially if you are going into production, then it's worth finding a vendor that has the knowledge.

As far as training for GD&T, it's not that tough to teach yourself the basics. You can get an ANSI guide that will give you clear definitions of various callouts and how to use them. That's how I got up going with it.