Expanded use of ALL AROUND Symbol
Expanded use of ALL AROUND Symbol
(OP)
This topic was addressed in thread 1103-200357 some time ago, without a definite resolution. I am bringing it up again for the members to comment on.
The ALL AROUND symbol was introduced in ASME Y14.5 in 1982 to apply to Profile of a Surface tolerance. It is also in paragraph 3.3.18 of the 1994 spec with the word "profile" missing, but in reference to a tolerance, verses a dimension.
The new 2009 spec also applies it in paragragh 3.3.19 relatuve to profile tolerance of all surfaces.
The new spec even introduces an ALL OVER "2 concentric circle" expansion of the principle for 3 dimensional application of profile of a surface.
So here is my question for debate: Is it proper or correct, using an "extension of principles" justification to expand the all around synbol to dimensional features such as radii extending around non circular features?
This is being used on radii drawings of parts at my place and is a topic of controversy among design and drawing check.
We have two ASME GDT certified people who think it is OK, and are using the "extension of principles" arguement as their justification.
As I read the standard, I believe it cannot be justifably expanded from tolerances to dimensional features, and should only be applied as the standard dictates.
What say you?
The ALL AROUND symbol was introduced in ASME Y14.5 in 1982 to apply to Profile of a Surface tolerance. It is also in paragraph 3.3.18 of the 1994 spec with the word "profile" missing, but in reference to a tolerance, verses a dimension.
The new 2009 spec also applies it in paragragh 3.3.19 relatuve to profile tolerance of all surfaces.
The new spec even introduces an ALL OVER "2 concentric circle" expansion of the principle for 3 dimensional application of profile of a surface.
So here is my question for debate: Is it proper or correct, using an "extension of principles" justification to expand the all around synbol to dimensional features such as radii extending around non circular features?
This is being used on radii drawings of parts at my place and is a topic of controversy among design and drawing check.
We have two ASME GDT certified people who think it is OK, and are using the "extension of principles" arguement as their justification.
As I read the standard, I believe it cannot be justifably expanded from tolerances to dimensional features, and should only be applied as the standard dictates.
What say you?





RE: Expanded use of ALL AROUND Symbol
I'm not sure I understand what you mean by "radii extending around non circular features". Do you mean applying the all around symbol to something like a fillet radius, in the same way that "TYP" is used?
Evan Janeshewski
Axymetrix Quality Engineering Inc.
www.axymetrix.ca
RE: Expanded use of ALL AROUND Symbol
Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services
RE: Expanded use of ALL AROUND Symbol
We do not use "TYP"---too vague.
RE: Expanded use of ALL AROUND Symbol
We apply the word "ALL AROUND" to any fillet or cham where needed. We eliminated the word "TYP" here cause of the same reason you mentioned, to vague.
I don't agree at all with your GD&T guys. How i understand it, this symbol only meant for GD&T. Plus i could see it being missed very easily on dimensions.
Solid Edge V20
RE: Expanded use of ALL AROUND Symbol
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: Expanded use of ALL AROUND Symbol
Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services
RE: Expanded use of ALL AROUND Symbol
RE: Expanded use of ALL AROUND Symbol
Sounds like to me there wasting time by doing it this way when its faster to just throw a note under it saying ALL AROUND.
So to answer your OP
"So here is my question for debate: Is it proper or correct, using an "extension of principles" justification to expand the all around synbol to dimensional features such as radii extending around non circular features?"
NO!!!!
Solid Edge V20
RE: Expanded use of ALL AROUND Symbol
RE: Expanded use of ALL AROUND Symbol
After reading your clarification, I say no. I don't see it as a valid extension of principle. Here are the reasons why:
First, the definition of the all around symbol specifically mentions the leader from the feature control frame. A radius or chamfer does not have a FCF.
Second, the definitions of "all around what" mention surfaces all around the part. A radius or chamfer would only apply to a subset of the surfaces all around the part (the fillet or chamfer surfaces, and not the flats and/or other surfaces in between).
Third, Profile is the only class of tolerance that can apply to a group of different feature types and hence can really be applied "all around".
Evan Janeshewski
Axymetrix Quality Engineering Inc.
www.axymetrix.ca
RE: Expanded use of ALL AROUND Symbol
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: Expanded use of ALL AROUND Symbol
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
RE: Expanded use of ALL AROUND Symbol
Solid Edge V20
RE: Expanded use of ALL AROUND Symbol
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: Expanded use of ALL AROUND Symbol
Easier just to write "ALL AROUND". Also less ambiguous. Also, less of a problem with pretty much all CAD systems.
I see no upside to using the symbol.
V
RE: Expanded use of ALL AROUND Symbol
"3.3.18 All Around Symbol. The symbolic means
of indicating that a tolerance applies to surfaces all
around the part is a circle located at the junction of
the leader from the feature control frame."
So from that you're only suppose to use that for feature control frame
Now, if you a company like the one i work for and don't abide by the letter of the ASME law. Than i would probably prove to them there wasting valuable, if they really are, doing it the way they are.
Solid Edge V20
RE: Expanded use of ALL AROUND Symbol
Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services
RE: Expanded use of ALL AROUND Symbol
You beat me too it! I was going to bring up that same point.
And the fuel piles higher...
David
RE: Expanded use of ALL AROUND Symbol
There are references in the spec that state that adding local notes to clarify situations like this are OK.
RE: Expanded use of ALL AROUND Symbol
RE: Expanded use of ALL AROUND Symbol
I'm not sure I understand that, JLang17.
If you are refering to a situation such as this example, how would you dimension it? "4X R.XX" or "8X R.XX", or "R.XX ALL AROUND"? If you use ALL AROUND, how is that different than using the circle? Intent is clear, isn't it? While it is not directly proscribed, this use is neither directly prohibited by the standard.
"Good to know you got shoes to wear when you find the floor." - Robert Hunter
RE: Expanded use of ALL AROUND Symbol
I would use ALL AROUND to dim this feature due to the rad including the corners of the part.
Now if the corners were not rad, it would be R X.X 4X
Solid Edge V20
RE: Expanded use of ALL AROUND Symbol
Ron, I believe you are working Government contracts, so I'd lean on the side of caution and not use it in the application you describe.
At my place, where most people dont' even know what ASME Y14.5 is, I'd probably allow it if the intent was clear. However, like cadmanI don't think our CAD does it automatically/intelligently so would discourage it for that reason.
KENAT,
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RE: Expanded use of ALL AROUND Symbol
RE: Expanded use of ALL AROUND Symbol
I am not so concerned that readers will misinterpret this callout applied to dimensions.
Any reader familiar with weld symbols or all around profile-of-a-surface tolerance will get the intent, but it was a real stretch for me when colleagues tried to use Y14.5 to justify. Besides, it's just easier to all the words.
Some of the posters above have given me more good reasons not to permit or perpetuate this practice.
RE: Expanded use of ALL AROUND Symbol
I Would like to comment simply to state that I, for one, have seen and used the "all-around" symbol on dimensions before, as there is no notation in the standards saying otherwise. The only time I woul use it, is perchance the definision of the symbol is absolte. Needless to say, there is an obvious meaning and no other posibility as to its use. Now if per say there was any, key word (any), chance of misinterpritaiton of the afromentioned symbol and it's meaning, then it's use in that situation shall be simply, no-go. I for one would rather use the symbol when possible, but I ensure that the situation would allow for it in my interpritation. I would also like to note that as some people may use it, and some people may not within any givin organization, I strongly recomend having an internal specification detailing the use of the symbol prior to implmentation.
V/R
Nathan
CAD Technician/ISO Director
Compass Systems, Inc. ( http://www.compass-sys-inc.com/ )
RE: Expanded use of ALL AROUND Symbol
There are notations stating otherwise, however. Check out the paragrahs I note in my OP.