Correctness of the gd&t symbol 2

Datum feature symbols A,B and C are attached to centerlines, which is incorrect.
They need to be associated with physical features of the part by being attached to either surface outlines or size dimensions of features of size.
Otherwise, it is ambiguous which features are used to obtain the datums and the datum reference frame.

Hi, nik007:

Also, the profile feature control frame needs to be attached to the surface or the extension line of dimension "3 x 612". It should not be aligned with dimension "3 x 612".

Measuring profile of the surface is easy. What you need to do is to establish datum first based on physical features rather than phantom lines.

Best regards,

Alex

Whoever drew this doesn't know how datums work...