GDT_Fundamentals of GD&T

1

2

3

Form Error

4

When the feature control frame is next to the size dimension, it is controlling the axis or center plane. An inspector must derive the median plane or median axis. This can be extremely time consuming and expensive to measure.

How to check flat surfaces? Same as FLATNESS tolerance??

How to check it if it cannot be rolled?

16.6 16.0

16.8

12.8

0.3