Concentricity vs. Runout

[bandersen4004]

I am working on modernizing technical data and updating specifications and GD&T for parts designed 50 years ago to be manufactured today. In ASME Y14.5 2018, concentricity was removed and it seems like it is recommended to use total runout instead. Is there an easy way to convert the concentricity tolerance to a total runout tolerance? Or would you suggest using something else in place of concentricity? Any and all help is greatly appreciated!

 

[Gr8blu]

Not a direct answer to your question, but ...

Concentricity – Elimination from ASME Y14.5 2018 Standard | GD&T Basics

The ASME 2018 Y14.5 GD&T Standard contains a few significant changes, including the elimination of the concentricity constraint. Check out this video article for more on this change!

www.gdandtbasics.com

 

[mfgenggear]

OP
Look at this post link

Runout Tolerance Applied on an Assembly - Drafting Standards, GD&T & Tolerance Analysis

Why runout is used in this figure? (instead of profile) What would be the difference between using profile (maybe even with dynamic profile modifier) instead of currently shown total runout? Are there any mathematical difference between shown total runout and profile (again with dynamic profile...

www.eng-tips.com

 

[mfgenggear]

OP
If taper on faces and diameters is required.
Then total runout is a good call.
If taper is not required standard runout
Would be a better choice.

 

[Garland23]

The best substitute for concentricity is usually the position symbol, not a runout symbol. That's because runout is a combination of location and form errors. But concentricity didn't really check for form.
Think about an oval shape: its center point could be perfectly concentric with a given datum axis. That's because the oval shape is still balanced (the old standard talked about "median points" and such). But a runout symbol would reject the oval shape purely because its form/shape causes wobble.

 

[mfgenggear]

Garland you ever work with shafts, no dice, true position is Taylored for holes. Or studs