thru versus thru-all -the final thread?

Hi all,

I know this has been brought approx. 1000 times before but I would love
to clarify what is the correct note (asme or ansi) for a hole going
into a tube.

Logic says that THRU would indicate throught the first face of the
tube. Whereas THRU ALL would be thru both sides of the tube, either
rectangular or round.

I think that notes such as 'this face only' and so on are helpful to
avoid confusion but I'm curious what the spec says about it (if
anything).

Thanks,

Zander

 

Right this minute I can't seem to find my copy of ASME/ANSI Y14.5, but
if I remember correctly it doesn't offer a recommendation to put THRU
after a hole callout. It CERTAINLY doesn't EVER mention the use of THRU
ALL. I spent years as a drawing checker and manufacturing liaison
person for some very well-known high-tech firms, and was regarded as the
company GD&T expert in those firms, and I'd strongly agree with you that
notes such as THIS FACE or FAR SIDE or THRU ALL are helpful, and that
THRU should really mean through only the face on which the callout
exists.

Regardless, if you'll note, when you define a hole using the Hole Wizard
as being Up To Next, you'll get an automatic hole callout of THRU
instead of THRU ALL (as you would when you define the hole as being
Through All).

'Sporky'

 

Thanks Sporky,

What happens to my drawings sometimes is that I will check it - see a
not like thru or a blind hole depth and immeidiately know and
understand it. Then - unbeknowenst to me, my drawings will end up at
an unknow fabricator with probably untrained personel (at blueprint
reading anyways) who will make several mistakes in a row such as - 1:
be unsure about a hole note and not ask anyone about it. 2:
misunderstand a hole note or other annotation or dimension etc. 3: act
on the preceeding 2 error resulting in scraped material. which leads
to 4: my customer calling and asking why the drawing doesn't explain
everything in 'plain english'. !!!!!!!

Zander

 

Zander & Spork,
As specified in ASME Y14.5M - 1994
- Section 1.8 Dimensioning Features
-- Sub-Section 1.8.1 Diameters
Where the diameters of a number of concentric cylindrical features are
specified, such diameters should be dimensioned in a longitudinal view
if practicable.
My Interpretation: If multiple diameters are involved, it is always
clearer to dimension diameters & depths in a section (side) view as
opposed to the plan view. In this way, there can only be one
interpretation per the print.
-- Sub-Section 1.8.9 Round Holes
Where it is not clear that a hole goes through, the abbreviation THRU
follows a dimension.
My Interpretation: The "THRU" abbreviation should be used for
clarification as needed. I have also worked in the capacity of a
Checker and have been responsible for company standards and meeting the
requirements of various specifications. Whenever in doubt, I have
always used the terms "THRU", "THRU ALL", "THRU ONE WALL", "THRU BOTH
WALLS", etc. Whatever it take so that there can only be on
interpretation and that the drawing stands alone. The last two
requirements are also per ASME.
Regards,
Eddie

 

Until next year when ASME Y14.5 - 2006 comes out...