ASME Part's list standard 2

[ViewGator91]

I am trying to find the ASME Y standard that governs replacing find numbers vs not replacing find numbers. I have found very open standards in global that basically state when you are changing fit, form, or function then you need a new find number on your parts list. How about when you are just changing a screw length? You just change the part no. and nomenclature then roll the rev on your drawing.

Does anyone know the ASME standard that states this?

Thanks

 

[KENAT]

If I understand your question it's more about whether to revise than about parts lists.

ASME Y14.100 probably gives the most explicit explanation of when a new part number is assigned rather than a new revision. I have the 2004 standard in which 6.8.1 is the relevant section.

My summarized version is if the part after the change is completely interchangeable with the old part (think the 2 parts could be put in a bin and either used), then it's a rev change. Otherwise, it's a new PN, however, due to the effort sometimes required in changing part numbers many places do not follow this to the letter all the time.

New PN may be required not just by physical interoparability but by being able to trace parts/when a change was cut in. For instance, say a treatment was changed from Cadmium to say Zinc for environmental or health & safety reasons. While the parts are still physically interchangeable, it may be necessary to be able to tell them apart for other reasons.

I have previously posted exerpts from this section, if not in this forum then over on forum781.

Form, fit & function gets trotted out all the time but is not the whole story.

KENAT,

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

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

What is Engineering anyway: faq1088-1484

 

[ViewGator91]

I am talking about a find no. on a parts list of an assembly drawing.

Say you have block (find no 1) being screwed to base (find no 2) by screw (find no 3).

The screw changes from .5" to 1", but is still a 1/4 screw/bolt.

Do you make it find no 4, and put deleted in the nomenclature of what was find no 3? Or do you just replace the part no/nomenclature of find no 3 to reflect this change and roll the rev of the drawing (and the final or top level assembly)?

 

[KENAT]

Oops, I think I mis-read your question first time. I'm sure a similar question came up before, if not on this forum then maybe on forum781.

Non mandatory D8 in Y14.100 talks about find no's but I'm not sure it's explicit on your subject.

Y14.34m-1996 has a little at section 4.5 and refers to Y14.35M-1997 which again doesn't have as much as you might hope.

KENAT,

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

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

What is Engineering anyway: faq1088-1484

 

[ViewGator91]

Thanks

 

[KENAT]

thread1103-218960 was I think the one I was talking about but I'm not sure we came to a conclusion:-(.

KENAT,

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

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

What is Engineering anyway: faq1088-1484

 

[fcsuper]

Form Fit Function. If the form, fit, function changes, then the item gets a new part number. This isn't in ASME that I remember, but an industry type rule.

The problem comes in when business needs push you in a direction to ignore the rule just to keep the flow of whatever flowing.

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]

fcsuper, I have come to hate the old 'form, fit, function' line as it really isn't the whole story.

KENAT,

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

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

What is Engineering anyway: faq1088-1484

 

[SWCADMAN]

Form, fit and function only applies to parts being revised.

In your case only the parts list is being revised.

Per ASME Y14.100: Items to be deleted shall retain the same Find number. The nomenclature shall be erased and the word “DELETED” inserted in the nomenclature or description column. When using digital data techniques, items deleted shall be omitted on the next list run or the word “DELETED” may be inserted in the nomenclature or description column.

...and no you do not roll the rev on the next or final assy.

Jorge

 

[KENAT]

SWCADMAN, can you point out where in ASME Y14.100 that is for my referenc. This question has come up before and I don't recall a definitive answer being found at that time so having the reference would be usefull for future reference.

Thanks.

KENAT,

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

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

What is Engineering anyway: faq1088-1484

 

[SWCADMAN]

Kenat,

ASME Y14.100-2004, APPENDIX D-13 "CHANGE REQUIRING NEW IDENTIFICATION" AND SECTION 6.8 "ITEM IDENTIFICATION"

ASME Y14.35M "Revision of Engineering Drawings and Associated Documents". SECTION 8 "ASSOCIATED DOCUMENT REVISIONS"

10th ed. DRAWING REQUIREMENTS MANUAL SECTION 23.23.5 "Deleting Items. Items to be deleted shall retain the same Find number. The nomenclature shall be
erased and the word “DELETED” inserted in the nomenclature or description column. When using digital data
techniques, items deleted shall be omitted on the next list run or the word “DELETED” may be inserted in the
nomenclature or description column."

Hope this helps,
Jorge

 

[KENAT]

Thanks SWCADMAN, however, those are ASME references I've looked at before and I don't see that they explicitly talk about dealing with parts lists in the level of detail the OP is asking about.

Obviously the DRM is more detailed but it's not an industry standard as such.

KENAT,

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

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

What is Engineering anyway: faq1088-1484

 

[SWCADMAN]

Kenat,

MIL-STD-100E SECTION 704.5 "DELETING ITEMS" has the same wording as the DRM. As you know MIL-STD-100E was superceded by ASME Y14.100, Y14.24, Y14.34M AND Y14.35M.

I think ASME Y14.35M SECTION 8 will have this same wording...unfortunately our copy at my job is missing this section...grrrrrr. I'll follow up when I get more info.

Jorge

 

[ctopher]

The suggestions by fsuper and SWCADMAN are how I have seen it for the past ~20 years.

Chris
SolidWorks 08, CATIA V5
ctopher's home (updated Aug 5, 2008)
ctopher's blog
SolidWorks Legion

 

[KENAT]

Sadly it doesn't say much as far as I can see. Section 8 of 14.35 is only about 3 sentances.

Section 4.1 talks about Deleting or Crossing out but only generally, not specifically about lists or whether find numbers can be re-used.

KENAT,

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

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

What is Engineering anyway: faq1088-1484

 

[drawoh]

ViewGator91,

Think hard before you implement this.

In SolidWorks, you can maintain item (find) numbers, and you can even cross items when the quantity reaches zero. When I tested this on a much earlier version, it was not reliable. I found it much safer to stick with item numbers that follow order of assembly. I never refer to item numbers in notes. SolidWorks always matches item numbers to the current parts list.

If they have fixed SolidWorksk now, or you are using a different 3D[ ]CAD package where this feature works, you can still have problems.

The drawing is at revision[ ]D. The assembly view sucks; nobody can make sense of it. In SolidWorks, I open the assembly model. I delete the assembly view. I rotate the asssembly model and re-create the exploded views. I generate a new view. Your modified parts list now is a replaced parts lists. In another scenario, your parts list gets corrupted, and you have to delete it and generate a new one.

In yet another scenario, you create a drawing and maintain the item numbers on the part list. The CAD software is upgraded with a completely new parts list program. You cannot switch over without blowing away your item numbers.

If you change form, fit and/or function, you generate a new part[ ]number.

JHG

 

[frankreid]

In my engineering services business I have done work for many companies in 4 western (US) states. I notice in this discussion there has been no mention of how to document the change, which may dictate how to make the change on the parts list.

In general practice it has been common to ignore the Revisions block for any detailed changes and to mention the Rev letter and reference there the EO or ECO number where the change is documented.

This means they will document everything in a separate document called an Engineering Order (EO) or Engineering Change Order (ECO).

If the change is to be a simple one, such as a screw length then it's just changed in the parts list and documented on the ECO with "IS/WAS" comments. Generally because it's a part not made by them.

If it is an engineering change to their part, such as a dimension between holes, then it is often shown in the parts list as "Deleted" and a new item number is added with the deletion and addition documented on the ECO and the change made on all locations of the drawing. If it's generated from a solid model (Catia, SolidWorks, Autocad) then the solid needs to be changed and the views updated.

But the original question, I believe, was whether that part number or item number can be reused once deleted. I've seen it both ways but it has become a standard practice at some companies to leave the number as "DELETED" for one revision letter change but then reuse it again after that. This way the documentation of the deletion remains in the system.

Frank Reid

 

[energised]

We follow ASME standard pretty closely as far as revisions. If the change is still a bolt, the P/N and size can be revised, keeping the same find no. If your assembly was reconfigured so much that now the fastener is not used than that find no. could not be used for other components. In solidworks you can drag the components around in the assembly tree and the drawing file will reorder after rebuilding, to maintain the note find numbers.

 

[sheevaraam]

I am sorry I don't really understand this question?? What is a find no?

 

[ctopher]

"What is a find no?"

It is "find number".
Page 21:

http://www.dtic.mil/ndia/2008technical/GastonEngineeringDrawings100G.pdf

thread1103-163911


Chris
SolidWorks 09, CATIA V5
ctopher's home
SolidWorks Legion