Y14.100 Revision Method

[HouTxMechPE]

Hello all. If any one can please assist me in changing my employers revision process I would greatly appreciate it. It has always been my understanding and practice that drawings begin life as Revision A (alphas) and once approved internally and submitted externally to a client or fabricator become Revision 1 (numerics). They are currently doing the opposite where I work and they would like documentation to state my claim. I believe it is located in ASME Y14.100 but if someone can verify that before we purchase it that would be greatly appreciated. A scan of the page or section would be incredible to find.

My experience has been to revise drawings according to this basic flow chart I made, see link. Please provide your inputs, thank you.

http://i68.photobucket.com/albums/i13/qwikkota/DrawingRev.jpg

 

[KENAT]

14.100 does give details on when a change constitutes a new part number or a revision. However, it doesn't say much on revision as such - this is in ASME Y14.35M

Y14.35M-1997 only mentions letter revisions. Section 5.1 "Upper case letters shall be used in sequence beginning with A... ...Initial issue of a drawing does not constitute need for a revision letter and may be indicated by the use of a - (dash)."

There is no mention of changing to numeric revs, or from numeric revs to letter revs that I see.

That said, I was under the impression that in the USA having numeric revs for pre release stage was fairly common, switching to letter revs at initial release. It's what we do (though our config control sucks so don't take that as a recommendation) and it's been mentioned in other threads I believe.

In the UK where I used to work, for govt jobs prototype contractor controlled drawings were to letters, once approved by the govt they were supposed to go to numeric revs.

The standard itself is copyrighted etc. and posting chunks of such docs on this site is discouraged and may be deleted.

I would suggest their current process is just fine and if it aint broke...

(FYI forum781 may have threads on related issues as may forum1103 )

Posting guidelines faq731-376

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

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

 

[PeterStock]

Our major client uses an initail release level of no rev(not even a dash). Prior to release there is a note on the drawing that it is preliminary as are any drawings being revised prior to their release. The first change is A then B etc. Most other companies I have been at use A for the first release. I also have seen use of rev 1,2,3 etc for prototypes. These had no formal release procedure for the most part.

Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services

http://www.infotechpr.net

 

[ewh]

My experience is different from yours... working with military contractors (who were definitely bound to the standards), we always used an internal scheme for pre-released drawings (p1 for first preliminary version, etc), releasing at rev "-" and using letters for any subsequent revisions. At my current employer (military sub-contractor), we use the same system, but release at rev "A".
As noted, the standard does not attempt to specifically control whether letters or numbers are used, and what should be used at initial release is only a recommendation, not a requirement. I have to admit a preference for initial release at "-" though for the sake of common sense... it is a rev level after all.;-)
As long as your employers procedure is well documented, it seems legitimate. If you can't justify changing the procedure in terms of $ & ¢, you'll probably have to learn to live with it.

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