Hole Callouts & Reference Dims
Hole Callouts & Reference Dims
(OP)
Hole Callout...
Square tube with a hole going through the entire part (both walls). The hole(s) are being located using a positional tolerance and basic dimensions. In this example, is best practice to call out the hole as one thru hole or two holes? We've always called this out as one hole thru but some are thinking because of the positional tolerance this should be called out as 2X.
Reference Question...
Here's an easy one. What is the best practice based on the most recent drafting standards for calling out a reference dimension?
REF
REF.
(xx)
Square tube with a hole going through the entire part (both walls). The hole(s) are being located using a positional tolerance and basic dimensions. In this example, is best practice to call out the hole as one thru hole or two holes? We've always called this out as one hole thru but some are thinking because of the positional tolerance this should be called out as 2X.
Reference Question...
Here's an easy one. What is the best practice based on the most recent drafting standards for calling out a reference dimension?
REF
REF.
(xx)





RE: Hole Callouts & Reference Dims
However, in none of their examples of coaxial holes do they use "2X".
Parentheses (xx) is the preffered method in 14.5-94 section 1.7.6. I doubt it changed in the latest version.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Hole Callouts & Reference Dims
Do not be ambiguous. Provide a drawing view that clearly shows the hole going through both sides of the tube. This can be a section view, or an isometric view. Even hidden lines on your side view would do it. Show the centreline going all the way through.
SolidWorks labels holes THRU or THRU ALL, depending on how much stuff they go through, but I cannot find this in the standard. There is no substitute for a picture.
RE: Hole Callouts & Reference Dims
For a ref dim, I add parenthesis around the dim.
Not to be confused with dual dims, they use brackets.
Chris
SolidWorks 09 SP4.1
ctopher's home
SolidWorks Legion
RE: Hole Callouts & Reference Dims
thread1103-257193: THRU, THRU ALL and Continuous Feature
Is your question primarily relating to how to correctly apply the positional tolerance to 2 coaxial holes or is it more about making sure the machinist knows the hole goes through both sides of the tube?
I assumed the former as you mention position. To address the latter, making it clear graphically should be enough.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Hole Callouts & Reference Dims
A pic for us to see would help.
Chris
SolidWorks 09 SP4.1
ctopher's home
SolidWorks Legion
RE: Hole Callouts & Reference Dims
And what about the other "three" 12mm holes going thru both walls? If the 10.5's should be called out 4X then to be consistent would the "three" be called out as 6X even though they do not have any positional tolerance (GD&T) and are simply located via a plus/minus tolerance? That isn't making sense to me either.
Thanks for your help folks!
Your thoughts...
RE: Hole Callouts & Reference Dims
Minor point on your excerpt, the 15 dimension looks like it should also be basic, but you probably know that already.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Hole Callouts & Reference Dims
Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services
www.infotechpr.net
RE: Hole Callouts & Reference Dims
Of course if the hole(s) subsequently become the datum (or maybe some other datum structure that doesn't spring to mind) then indeed the 15 shouldn't be basic, hence the soft wording in my post.
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?