THRU, THRU ALL and Continuous Feature 1

[fcsuper]

I recently asked this quest in the Y14.5 yahoo group and got some interesting answers. Here's the question: I was just curious in seeing what is currently being done by others with the use of "THRU" on cut features. When is it necessary (if at all). What is the difference between "THRU" (whether necessary or not) and "THRU ALL". And, has anyone starting useing the boxed CF symbol (continuous feature) from ASME Y14.5-2009 (and how)?

Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group

 

[KENAT]

That's what I was trying to tell 'em;-)

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[JonSelby]

Does anyone have a view on whether the abbreviation 'THRO' is an acceptable alternative to 'THRU' ?

I notice most people refering to ASME Y14 so just to add another spin ... according to BS8888 there are two points I can glean.
1. One should assume that a hole is 'through' unless specifically shown otherwise. It is however acceptable to use additional 'notes' if the design intent would otherwise be ambiguous.
2. It is strongly advised that the use of abbreviations be kept to a minimum. If necessary they prefer that one should write the word in full to avoid ambiguity. The principal behind this is that a technical drawing should transcend language barriers.

Be interesting to hear you thoughts on my first post!!!
Cheers, Jon

 

[KENAT]

Jon, I'm pretty sure we used to use THRU back when I was working in the UK. BS8888 is essentially a compendium of the relevant ISO and similar specs so they'd probably emphasize the language barrier issue more.

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[BiPolarMoment]

So that strong advisement for min. abbr. is coming from a BS spec and not thru ISO or ASME? ;-)

 

[fsincox]

fcsuper,
I would like to know why they didn't just go with CZ (common zone) like the ISO have been doing for years.
Are we really interested in standardization or not?
Frank

 

[fcsuper]

I'm not sure. But ASME and ISO are both lacking in different areas. It may seem that ASME tends to err on the side of caution from a litigation standpoint and ISO from the standpoint of inspection/quality-systems. But there's plenty of areas that are good regardless those, which either standard would do well to adopt from the other.

Matt Lorono
Lorono's SolidWorks Resources & SolidWorks Legion

http://groups.yahoo.com/group/solidworks & http://twitter.com/fcsuper

 

[Tunalover]

Use of the word THRU is redundant because when a hole specifies no depth it is understood to be through. In situations where hold penetrates a single wall with another wall behind it a section view is mandatory. I think you'll find that the word THRU is not even defined in Y14.5!


Tunalover

 

[Tunalover]

A hole with no depth callout is a through-hole. In situations where there may be a secondary wall behind the first penetration then a section view is a must. The word THRU is defined nowhere in ASME Y14.5M-1994.


Tunalover

 

[ewh]

Cant' argue with that, other than to remind that old habits die hard. While there may not be an explicit definition for "THRU" in Y14.5, it is used in some examples, at least in the '94 version.

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]

 

[KENAT]

Where it is not clear that a hole goes through, the abbreviation THRU follows a dimension

Maybe your copy of the standard has a page missing tunalover. Heck, I already posted this above at 22 Oct 09 11:23 you guys aren't even trying.;-)

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[ewh]

Thanks for that, KENAT. I see that it is also in the '09 version.

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]

 

[fcsuper]

It is hard to miss specific topic in the ASME standard when just skimming through. The index of is no help on most searches too. Maybe this is a good reason to by the PDF version of the standards?

Matt Lorono
Lorono's SolidWorks Resources & SolidWorks Legion

http://groups.yahoo.com/group/solidworks & http://twitter.com/fcsuper

 

[Tunalover]

KENAT-
Good catch. Thanks for straightening me out.


Tunalover

 

[ctopher]

Per Kenat is how I have always noted thru holes. If the part has another feature in the way of the hole that I'm also going thru, I indicate "Thru All".

Chris
SolidWorks 09 SP4.1
ctopher's home
SolidWorks Legion

 

[KENAT]

I didn't find it first look, fcsuper had to point it out to me.

I still haven't been able to find where in 14.5 it says that "A hole with no depth callout is a through-hole" even though I've often heard this said, and used it myself.

In fact 1.4b kind of implies this wouldn't be the case "...nor assumption of a distance or size is permitted...".

Maybe I'll actually increase my use of 'thru'.

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