How to Annotate Holes Passing Through One Surface of a Part 1

[axym]

Hi All,

This one might seem obvious, but I'm not a drafting expert.

I have a part with a square tube, that holes are drilled into. The holes go all the way through the "top" layer of the tube, but not through the "bottom" layer. What is the best way to indicate this on the drawing? Do I use the word THRU?

Evan Janeshewski

Axymetrix Quality Engineering Inc.

http://www.axymetrix.ca

 

[powerhound]

If the hole only goes thru one wall only then I specify the hole size and tolerance and put "NEAR SIDE ONLY". Of course the hole has to be shown in the view that makes it the near side.

Typically THRU means thru everything, both near and far side.

John Acosta, GDTP S-0731
Engineering Technician
Inventor 2013
Mastercam X6
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II

 

[KENAT]

Add a section view - that's the most robust way.

All this thru next, thru one wall... terminology can occasionally be misunderstood - especially if there are any language issues between drafter, vendor & inspection...

Posting guidelines faq731-376

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(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[Tenkan]

If you do enough or specialize in those type of parts maybe consider adding thru and thru-all definitions to your company standard for your vendors, then you could simplify your drawings accordingly. Otherwise, add the appropriate views or notes for clarity to show the hole does not go thru all.

lightweight, cheap, strong... pick 2

 

[fsincox]

Koda94,
Appairently SolidWorks thinks "thru" and "thru all" are different, too. I was shocked the first time I saw that as I thought like powerhound.

 

[CheckerHater]

If there is any possibility that your hole call-out may be misunderstood, the best way to clarify this on the drawing is to provide section thru the hole in question.
In today CAD systems it takes less time to create a section than to type in "NEAR SIDE ONLY".
Also as the hole goes thru second wall it becomes “2 HOLES”
This two techniques together will give bullet-proof hole designation, but also could be used separately.
Grumpy old drafter in me reminds that back in time we used to create a section thru every semi-important hole using only paper and pencil and no-one died.

 

[dgallup]

Yeah, but you probably did it on D size paper. Now everyone wants to be able to see it all on a single sheet of A size paper. But I agree with you.

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[randy64]

We use the note "THRU ONE WALL ONLY".

If we want it to go all the way thru, we just say "THRU" and use a composite positional tolerance.

 

[fsincox]

I believe some ISO countries prefer showing hole callouts in sections, where, we tent to call them out in the "circle view", true?
Frank

 

[Tenkan]

its true the difference between thru and thru all is not clear, despite what Solidworks thinks. For me it comes down to the complexity of the part and the respective drawing views and detail like hidden lines. If its not clear the hole does not go thru all, then I use a note or section view.

lightweight, cheap, strong... pick 2

 

[KENAT]

Yeah, for a relatively simple part you could get perhaps away with showing hidden detail but it's still not as robust as adding a section.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[axym]

Hi All,

Thanks for all the input. It seems that this is more of a best practice issue, as opposed to there being hard and fast rules.

The designer went with the NEAR SIDE ONLY annotation.

Evan Janeshewski

Axymetrix Quality Engineering Inc.

http://www.axymetrix.ca

 

[fcsuper]

ASME standard states that where it is not clear that a hole is thru, then use THRU. Additional notes are allowed for clarity "where multiple features are involved". It doesn't say what the additional notes should say. Some have interpretted this to mean they should say "THRU ALL" for cutting through multiple features. I think the opposite. I think "THRU" means through the part, and you only need clarification when you are going through some but not all features of the part.

Ref: ASME Y14.5-2009 1.8.10 Round Holes

Matt Lorono, CSWP
Product Definition Specialist, DS SolidWorks Corp
Personal sites:
Lorono's SolidWorks Resources & SolidWorks Legion

 

[CheckerHater]

Not to hijack the thread, but doesn’t “hole” going “thru” several features create condition shown, for example, on Fig-7.44, 7.49, 7.50 and others?

 

[powerhound]

In those cases, no note would be necessary since the intent is clear per the view shown.

John Acosta, GDTP S-0731
Engineering Technician
Inventor 2013
Mastercam X6
Smartcam 11.1
SSG, U.S. Army
Taji, Iraq OIF II

 

[pmarc]

Some have interpretted this to mean they should say "THRU ALL" for cutting through multiple features. I think the opposite. I think "THRU" means through the part, and you only need clarification when you are going through some but not all features of the part.

In the light of what is shown in fig. 7-5 from Y14.5-2009 your interpretation seems to be different than Y14.5's.

 

[CheckerHater]

OK now, will somebody suggest unambiguous way to distinguish between Fig-7.44 that shows “4 holes” and Fig-4-5 that only has “6 holes”?
When hole drilled thru several walls becomes pattern and when it stills the one single hole?

 

[pmarc]

That is the problem with fig. 7-5 -- it seems like notation THRU BOTH SIDES together with "6X" and not "12X" made each pair of holes acting like continous feature.

 

[CheckerHater]

There is a bitter irony in the fact that 2009 actually introduced “continuous feature” symbol.
Should <CF> be added to DIA 25.6/25.0 on Fig-7.5 it would be perfect by the word and the spirit.
Should it be added to the “shortcomings” list? For something 15 years in the making 2009 has a few “half-baked” discrepancies like that.

 

[pmarc]

With "6X" specified, <CF> should be added to DIA 25.6/25.0.