huangyhg

use of "all around" circle symbol
i have been using this all around symbol for profile only (as was mandated in 1982 y14.5) but was reminded by a colleague that para 3.3.18 of the 1994 y14.5 dropped the word profile out of the paragragh, thus opening it up to be used for such things as radii or chamfers all around.
i am curious as to what the rest of you are doing regarding this. do you use the circle on the leader bend for radii, chamfers and the like?
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follow up to my post: i am still not comfortable using this for other callouts since the paragraph still refers to a "tolerance" relative to surfaces vs a feature size. what do you all think?
i use it the way you showed me ron.
quote:
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. see fig 3-17
so i鈥檇 say as defined here it only applies to tolerances (i added the caps), not explicitly to the dimensions them selves.
as such i鈥檓 not sure that technically this paragraph does really apply to chamfers etc.
however, i can see the usefulness for using it on the applications you describe.
i鈥檝e seen it on weld symbols, not sure if aws??? explains its use in this context.
kenat, probably the least qualified checker you'll ever meet...
y14.5 borrowed it from the weld symbol, ken.
3.3.18 is identical to the old para 3.4.2.3, of 1982 version minus the word "profile", so i think i am right in not wanting too use it for other non-fcf features as my colleagues are doing.
"... tolerance applies to surfaces all around the part..."
i'd be inclined to agree with you.
kenat, probably the least qualified checker you'll ever meet...
6.5.1 profile tolerancing.
(a) an appropriate view or section is drawn showing the desired basic profile.
(c) where a profile tolerance applies all around the profile of a part, the symbol used to designate 鈥渁ll around鈥?is placed on the leader from the feature control frame.
6.5.2 tolerance zone.
(a) profile of a surface. the tolerance zone established by the profile of a surface tolerance is threedimensional, extending along the length and width (or circumference) of the considered feature or features. this may be applied to parts having a constant cross section as in fig. 6-12, to parts having a surface of revolution, or to parts (such as castings) defined by profile tolerances applying 鈥淎ll over鈥?as indicated below the feature control frame.
6.5.1(a) would indicate that the profile is orientation dependant - i.e. the view in which it is placed controls the limits in that direction only, with (c) applying to the entire perimeter of the indicated shape.
6.5.2 might be better applied to compound curvatured surfaces and for generic "all over" applications
fig. 6.12 show an example with 45掳 corners.
ok dreamweaver, i knew about para. 6.5.1(c). but again, this is all about profile, which only reinforces my belief that the all around symbol is not for dimensional callouts such as corner radii and chamfers. fig 6.12 is about profile---not 45 degree chamfers.
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