ANSI Y14.5M 1982 and use of TYP

[EnJaNir]

Is the use of TYP or Typical acceptable and if so can someone point me to a reference that calls that out?

I have an orange copy of Dimensioning and Tolerancing ANSI Y14.5M -1982. On page 18 1..9.5 Repetitive Features or Dimensions it specified you can use "X" but I see nothing regarding TYP/Typical.

Thanks

 

[ctopher]

Try here:
thread404-200811

Chris
SolidWorks/PDMWorks 08 3.1
AutoCAD 08; CATIA V5
ctopher's home (updated Aug 5, 2008)
ctopher's blog
SolidWorks Legion

 

[fcsuper]

ASME Y14.5m-1994 does not restrict the use of TYP. It only states the preference to use X. TYP is still OK, but if you do use this, you should mention it in your internal drafting standard.

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

 

[CheckerRon]

Matt says TYP is still OK, and those not working to Y14.5, or working to the old '82 standard probably still use it.

Most of use, however, have stopped using TYP or TYPICAL years ago, because it is vague.

IAW Y14.5-1994, we prefer using exact number of places e.g. "5X" on a detail feature callouts, and "5 PL" or "5 PLACES" on an assembly item callouts.

"TYPICAL" is kind of lazy, because you don't want to bother counting and specifying the totals.

 

[ewh]

I'm with you, CheckerRon. It may be permissable per the standard, but it is not preferred.

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

 

[EnJaNir]

Thanks everyone. I just wanted to determine if it was in fact ok.

The only place where I/others am/are using it is for non critical features (ie grid patterns or to add a radius to remove sharp corners) in sheetmetal parts. All other critical areas are being called out as 4X etc.

 

[fcsuper]

EnJaNir,

Yup, I think that's a good rule to follow if your organization is using the term.

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

 

[MadMango]

The frustrating bit is that AWS A2.4:2007 (see 5.11.3) still allows the use of TYP and TYPICAL in weld symbols.



"Art without engineering is dreaming; Engineering without art is calculating."

Have you read faq731-376 to make the best use of these Forums?

 

[MechEng2005]

I often use "TYP" for weld symbols (although the external and internal drafting standards where I work are all but non-existant). I think with weld symbols, it is a lot cleaner.

Also, I would argue that in some applications, it makes more sense to use "TYP" without the number of places specified. For example, if the part is likely to be modified slightly and reused in other applications. Say I had a plate 12" X 12" with 16 holes on a 4X4 pattern. If I thought in the future somebody might use the same type of design for a 24" x 24" plate, which would need an 8X8 pattern for a total of 64 holes, I would be tempted to specify the holes as "TYP". This would allow the part to be copied and modified with less risk of somebody missing it and leaving the holes as an 8x8 pattern with the callout still listing only 16 holes.

In addition, where I work we have a place in our title block to specify "Open holes _____ unless otherwise noted." I think that actually putting "TYP" on the drawing is MUCH BETTER than allowing this title block note to specify the size. I personally do not use the title block note.

At least if I forget to put in a dimension for a hole, it is undefined, and the person making the part will have to come and ask. If I have a size in the title block and forget to put a dimension on a hole (that should be at a different size than listed in title block), the part will come back with the wrong size hole, and possibly need to be re-made from scratch.

-- MechEng2005

 

[CheckerRon]

Like most everyone else. I used to use TYPICAL on my weld symbols, but I now prefer using 2X,4X etc. in the tail of the symbol for an identical joint in 2 or more places.

This bother some people who argue that since it's not in AWS 2.4, I shouldn't be applying 2X from Y14.5 to welds.

Even for a nit pickin' (not chicken) checker like me, this is a bit much. If either spec or the company DRM doesn't prohibit it, why not use a more exacting method of callout?

 

[KENAT]

thread1103-160864 In case you didn't already go there from Chris's link.

It's come up a few times in the last couple of years. I'd generally avoid it but not sure I can confidently say it's forbidden.

The above link does point out that it's not universally understood or defined in a spec though, which for me is a good reason not to use it.

KENAT,

Have you reminded yourself of faq731-376 recently, or taken a look at posting policies:

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