hole thru into section - correct drawing note?

[hobbs101]

Hi. If I have a plate and with a hole through the plate, I put on the drawing 'M6 THRU'. That's clear.

But, if I have a box section and I want the hole to just go through the wall of the box section, what is the standard notation? I've previously stated 'M6 THRU SECTION WALL', but that sounds a little clunky.

Following on from that, if I have a fabrication of a 10mm plate welded onto the side face of a box section and I want the hole to go through the plate and the wall of the section then what's the notation? 'M6 THRU PLATE AND WALL OF SECTION'?

What if I actually want it to go all the way through? 'M6 THRU PLATE AND BOTH WALLS OF SECTION'?

What does the term 'THRU' actually mean? I normally take it to mean through to the next void. Is this correct?

Hobbs101
Mechanical Design Engineer

 

[randy64]

Check out this thread:

http://www.eng-tips.com/viewthread.cfm?qid=373265

 

[hobbs101]

Thanks. One day I'll learn to search the forums before posting!!

I'm going to adopt the 'one wall' terminology. Seems clear to me.

Hobbs101
Mechanical Design Engineer

 

[KENAT]

Sorry that's your take away from that thread.

I'd hope your take away would be to use a section whenever practical to clarify such matters.

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[hobbs101]

Kenat, I agree that generally a section would be the clearest. In my current case sections are not the most practical. I have a complicated fabrication with many holes. To my mind me using 'M6 THRU PLATE AND ONE WALL' and 'M6 THRU PLATE AND TWO WALLS' is clear.

Hobbs101
Mechanical Design Engineer

 

[KENAT]

Ah, but what about to the subsequent users of the drawing, is it clear in their minds?

I've seen instances of it being misunderstood and hence don't like it.

Obviously if you share 3D CAD date, even only as reference, this concern may be reduced.

Posting guidelines faq731-376

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

 

[hobbs101]

When I say 'to my mind it's clear' I mean I think it's clear to everyone! But, yes, I accept your points. Clarity can save many subsequent issues. In fact, I do have one instance where my adopted terminology isn't clear, so I have indeed put in a section .

Hobbs101
Mechanical Design Engineer

 

[ModulusCT]

If a drawing shows a hole feature, and there is no visible geometry 'behind' the hole, or within it, then it is assumed to be a thru hole, unless otherwise stated. However, I don't believe it's incorrect to say Mx THRU if it's a thru hole.

If the hole goes thru, but it's not entirely clear from the view, then you can state that the hole is a "THRU" hole... However, in some cases, where your hole only goes through one wall, and not the other, or any situation similar, best practice is to show a section view and dimension the depth of the hole directly. Don't allow (incorrect) interpretation, by removing all doubt whenever possible.

Mod

 

[juergenwt]

One view of the print should show a tapped hole on one side only. That is what prints are for. If you write all kinds of explanations on a print - how will someone in the rest of the world understand you? The world of manufacturing is global. That is one reason why we have ISO tolerances available to us. Your ISO print will tell anyone in the world what kind of a fit you want. If you write "press fit" on a print - it means something entirely different to someone in Poland than what it means to someone in Italy.

 

[CheckerHater]

And?

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

 

[mcgyvr]

My cad program simply does this..

 

[JNieman]

Automatically generated text in a CAD software is far from an authority on anything.