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All around symbol callout

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SeasonLee

Mechanical
Sep 15, 2008
912
The all around symbol is a circle placed on the bend of the leader line of a profile control; this symbol indicates that the profile tolerance zone applies all around in the view on which it is shown.

This is what I know of the all around symbol application, but recently I noticed it was used to indicate the root radius all around on a shank as shown on the attached dwg, I am wondering is it the right way on the all around symbol application ?

Thanks

SeasonLee
 
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SeasonLee
Here's a link in this forum where it was talked about
To sum the thread up. The all around symbol is meant for GD&T only. It is not a drafting standard per say. Lots of CAD system does not have a option to put that symbol on unless it GD&T

Solid Edge V20
 
The all around symbol and now the all over symbol are used with profile of a surface. The application shown on a radius does not conform to either the 94 or the 09 standard.

Dave D.
 
As long as the message delineated by the use of the symbol is unambigious and you describe this special usage in your companies drafting standards then I would say that using the all around symbol for other non-profile scenarios is acceptable.

HOWEVER, the use of the all around symbol in the example you provided is redundant and completely unnecessary. This is because the radius callout itself is enough to specify the desired results.

Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
 
Also, now that I had to chance to look this up, the All Around symbol does have other uses. It is use in weld symbols in the same fashion shown on your radius callout. Again though, it is redundant on this particular drawing.

Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
 
I believe that Y14.5 adopted the all-around symbol for profile controls from the welding standard. Those are the only two prescribed uses that I've seen for it. Outside of those two contexts, the symbol is not documented as for its meaning, so it would be difficult to defend its expanded use.
As pointed out, the use outlined in the OP is inappropriate by drafting conventions which indicate that the radius is continuous unless specifically indicated otherwise.

Jim Sykes, P.Eng, GDTP-S
Profile Services TecEase, Inc.
 
It would be correct use were it a weld symbol.

Adding an all-around symbol here, in addition to not following the standard when used in this manner, provides no information: If you delete it, the junction shown is one between a cylinder and a perpendicular flat surface -- that's a fillet, and the fillet radius is shown.

It appears to me that the Y14.5 all around symbol was originally borrowed from AWS 2.4 for welding. But it is in practiced used a little different. Without having the requirement that the all around symbol operate in the current view, significant drawing ambiguities would likely result in complex part drawings. With welds, you're only concerned with a weld joints and the number of permutations is hence smaller, so you can get away with being less specific.
 
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