implied positional tolerance?
implied positional tolerance?
(OP)
Can anyone tell me if there is an ASME fundamental rule that applies to position of features shown on the same centerline with no positional tolerance?
I see many drawings where features are implied on the same centerline but a positional tolerance is not given (or no dimensions from each feature to the centerline). What controls their implied position to each other, and if this is not standard practice is dimensioning a feature to a centerline appropriate?
Some examples are a shaft with two diameters, or a part with a slot placed on center where the centerline is shared. I’m trying to argue the point but its been countered that’s the way its been for years so I wanted to find out if there was any implied centerline standard that I’m not aware of.
I see many drawings where features are implied on the same centerline but a positional tolerance is not given (or no dimensions from each feature to the centerline). What controls their implied position to each other, and if this is not standard practice is dimensioning a feature to a centerline appropriate?
Some examples are a shaft with two diameters, or a part with a slot placed on center where the centerline is shared. I’m trying to argue the point but its been countered that’s the way its been for years so I wanted to find out if there was any implied centerline standard that I’m not aware of.
lightweight, cheap, strong... pick 2





RE: implied positional tolerance?
This kind of question comes up regularly take a look at some of the previous threads - I think at some point I typed out a chuck of the standard http://www.eng-tips.com/search.cfm?pid=1103&ac....
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: implied positional tolerance?
my apologies for the redundant thread, I'll take some time to search topics in the future.
lightweight, cheap, strong... pick 2
RE: implied positional tolerance?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: implied positional tolerance?
lightweight, cheap, strong... pick 2
RE: implied positional tolerance?
http://www.amazon.com/Dimensioning-Tolerancing-Y14...
That said, it's a bit disconcerting that your company isn't willing to shell out a few bucks for a proper reference. In my opinion, the Y14.5 standard is required to produce clear blueprints... unless you're some sort of a savant and have the whole thing memorized... or just never make anything very complicated.
RE: implied positional tolerance?
RE: implied positional tolerance?
Just depends.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: implied positional tolerance?
I just have an impression (perhaps wrong) that the initial question wasn't limited to '94, but to ASME Y14s in general.
RE: implied positional tolerance?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: implied positional tolerance?
As far as the suggestions they are all great. I personally would rather keep up with the standards and get the 2009, but I didn’t think to look on amazon for a used copy. Although its more like $65 for the 94 standard used that’s within reach for a personal copy that would only help in any situation.
lightweight, cheap, strong... pick 2
RE: implied positional tolerance?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: implied positional tolerance?
lightweight, cheap, strong... pick 2
RE: implied positional tolerance?
My guess is most decent trainers can still offer either version.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: implied positional tolerance?
But Kenat is right, most of training companies still offer classes per '94 standard. These courses will not dissapear just like that, I guess.