Basic dimension puzzler

[MintJulep]

I'm looking at a drawing produced by a well-known international company.

The title block does not claim compliance to any drawing standard.

There are linear dimensions with +/- tolerances placed inside boxes - as one might expect a BASIC dimension to be.

Any guesses as to how to interpret this?

Yes, I will of course ask the drawing creator. Or more accurately tell them NFG.

 

[Belanger]

I think your instincts are correct -- lower the boom on 'em!

The only other thing I can think of is if it's not a rectangle but rather a "hot dog" or oval -- some companies use that symbol for "critical" dimensions. Are you looking at a crisp picture, or is it fuzzy and this oval might be a possibility?

John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems

http://www.gdtseminars.com

 

[prdave00]

I'd speculate this is a way to distinguish some dimensions apart from the others. Maybe an "inspection dimension" or a dimension that changed from the prior revision of the drawing.

 

[Belanger]

Right -- apparently they wanted to do something to set those dimensions apart, and they probably didn't realize that a rectangular box has its own predefined meaning in the world of geometric tolerancing.

John-Paul Belanger
Certified Sr. GD&T Professional
Geometric Learning Systems

http://www.gdtseminars.com