Profile of surface 1

[waqasmalik]

Hi all, I have confusion in understanding the significance of primary datum reference "A" in feature control frame of profile of surface.If i remove Datum refrence A what will be the effect on callout?
Thank you in advance.

 

[CheckerHater]

Imagine your part being placed into chuck for inspection.

[A] being primary datum allows for greater misalignment between feature B and controlled surface.

 

[pmarc]

waqasmalik,
This may help you:

http://files.engineering.com/getfil...98bf-4824-aa0e-fc7bb8c9b8f3&file=fig_4_37.png

 

[greenimi]

Thank you pmarc

 

[waqasmalik]

Thanx a lot pmarc and checkhater,