Hello all,

I need some help with gd & t. I'm new to this.

Say, If I have just a rectangular box with two circular holes in it what dimensions should I label and where is gd & t helpful. If possible please explain the function of datums, straightness, flatness, perpendicularity, parallelism etc. specific to this example.

If there are any good beginner sources on the Internet that would be helpful.

Thank you.