unreferenced datum?

[Tmoose]

Attached is a screen shot of a drawing I'm being asked to approve.
One hole has been assigned as Datum A. Several holes' 2D positions are dimensioned from it, each with a simple ± tolerance.
No dimensions use "feature control frames" , so there are no dimensions with specific references to Datum A. True position etc.

Is it necessary to assign a datum ?
Is it "wrong" to assign a datum ?

thanks,

Dan T

 

[powerhound]

Is it necessary? No.

Is it wrong? While it isn't hurting anything, my answer is yes. If a datum is not referenced, it shouldn't be on the drawing.

John Acosta, GDTP Senior Level
Manufacturing Engineering Tech

 

[TheTick]

It is hurting things. It causes confusion and delay, thus costing money.

It also makes the company look bad. Get this monkey some training.

 

[mkcski]

It has no triangular foot, so it might be a symbol with another meaning not related to GDT - like maybe a feature with an inspection characteristic.

Certified Sr. GD&T Professional

 

[CheckerHater]

Or "hole marked "A"

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

 

[mkcski]

CH: I did read post-text. But but is the OP assuming the square box alone is a datum?
When the symbols are not per the standard, interpretation can be misleading at best.

Certified Sr. GD&T Professional

 

[CheckerHater]

I agree

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future