The term ALL AROUND 1

[Dawg2012]

Hello all,

I am looking to defend NOT using the "ALL AROUND" term (not the symbol) for a chamfer call out on a round hole in a section view. The follow up to that would be for a chamfer on a slotted hole.

I've always thought any non-broken feature (like a chamfer on a slot) would not require the term "ALL AROUND". A broken edge however - one that propagates around a sharp - would require it.

Ultimately I can't find it stated in 14.5-2009, and I don't think there's another 'dimensioning' standard under Y14.100... Where is it's usage documented?

Thanks in advance for any help.

 

[Belanger]

Check out paragraph 1.4 in the 2009 standard (page 8). It says that "Unless otherwise specified, all tolerances apply for full depth, length, and width of the feature."

 

[Dawg2012]

That seems to speak to the tolerance specifically, not the dimension.

There may be a similar implication for a dimension - that it defines the size of a 'feature'... and if that feature continues along a tangent edges it's still considered one feature.

 

[looslib]

Y14.5-2018 paragraph 6.3.19: For orthographic views, the symbolic means of indicating that a profile tolerance or other specification applies to surfaces all around a feature of group of features, in the view specified...

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Ben Loosli

 

[Dawg2012]

@looslib That's a nice refinement on para 3.3.19 in 2009 adding the clause 'or other specification'. We are using 2009 presently but that will be handy once we switch.

The question remains - would you be required to use that symbol on a chamfer dimension on a round hole in an orthogonal section view? How about a chamfer on a slot?

Other than the CAD file and common sense - what governs the understanding that these features are ALL AROUND, and when that needs to be clarified?

 

[CheckerHater]

and when that needs to be clarified?

When your drawing is confusing, or, as ISO elegantly put it in TPS (technical product specification) definitions:

A TPS is not complete if there is more than one possible interpretation of the specification.

When it's not clear from your drawing that features are all around, you have to explain yourself.

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

 

[Hallec]

A chamfer indicated in a section view of a threaded hole, or similar feature, is understood to 'wrap' around the entirety of the feature. If that were Not the case, then clearly defining the extents of the chamfer would be necessary... Therefore, the lack of such definition indicates that the feature does, in fact, apply all around the periphery of the hole. The same goes for a slot, or any other continuous, unbroken tangent edge(s).

One thing that can be done to fully ensure this is understood is to simply ensure that the features true profile is visible in at least one view. So, the chamfer may be called out in a section, but it's visible in another view which shows exactly the extents of its application.

The all around symbol is there, I believe, to simplify situations where a feature, process or other condition applies on multiple adjacent edges, seams, surfaces, etc., yet it's not advantageous to call out all instances individually. It's there to aid in the production of a clear, concise (uncluttered), legible, and easily understood, fully defined drawing.

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