Single document containing p/n with and without dash numbers.

[James7443]

I have some documents that have both an assembly p/n and machined component p/n. Is it acceptable per ASME Y14.100 to have the assembly use a base p/n and the machined part use a base p/n plus a suffix (-dash).

Example: Assembly p/n is ABC1234 and the Machined part uses p/n ABC1234-5.

Please include any specification and paragraph support either acceptable or not acceptable position.

Thanks,

Ron

 

[drawoh]

Ron7443,

The part number ought to point to an engineering drawing. On which drawing are the dimensions for your part?

--
JHG

 

[KENAT]

Sounds like you have a detailed assembly drawing per ASME Y14.24-1999 - is that correct?

I'd take a look at that standard, specifically section 4 & example Fig 8. From a real quick read it's not entirely clear.

The example drawing does not appear to assign different part numbers - only find numbers on top of presumably the assy part number - but not 100% clear.

The section on inseparable assemblies - which might also cover you - does mention at 4.2.3 (a) 'unique identifier for all items which become a part of the inseparable assembly' but it's not clear to me if this means part number or just he assembly part numbe + the find number.

I rarely do detail assembly drawings because of the configuration control issues. My only exceptions are when they are really inseparable assemblies but it's easier to detail the parts unassembled or occasionally for one off tooling or similar. In these cased I just have a part number for the finished assembly, the individual components only have their 'find' number.

Posting guidelines faq731-376

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

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

 

[swertel]

I'd also check how the parts are used downstream.

For example, it may be an inseparable assembly, but if the component parts are going to be fabricated outside, or inventoried until assembly, then you will want to create a unique identifier for them. Trying to plug in the {base number + find number} into your ERP/MRP system doesn't work well.

--Scott
www.wertel.pro

 

[ctopher]

I only do the dash numbering on tooling drawings/parts, because they stay in-house and can be tracked.
Production parts/assy's all have their unique P/N and associated drawings.
Using a dash number on a part that uses the same base number as the assy can be a mess if the part is used in another assy.

Chris, CSWP
SolidWorks '16
ctophers home
SolidWorks Legion

 

[James7443]

Thanks KENAT and Scott for your responses.

I agree that the drawing falls under the category of a detailed assembly drawing or possibly an inseparable assembly.

I think I have found my answer in Y14.100-2004 para D-9.6 which states "Where more than one item is described on a drawing, unique identification shall be provided by the addition of a suffix identifier, with the following limitations." I take this to mean that all items, assembled part and individual component, need to have a suffix (-dash).

The limitations (e) then states "Once assigned, PIN's shall not be changed except as permitted by sections D-10 and D-13. When additional items are added to a drawing, the PIN's of existing items shall not be changed, even if no suffix identifier was originally assigned." So I read this as stating that since, in my case, the base number (ABC1234) was used for the assembly (and I should clarify that the number also appears in our MRP system so it must be defined as published) I should not apply a suffix to it. The individual machined part does have a suffix (ABC1234-5).

I am thinking that the answer to my original question, "Is it acceptable per ASME Y14.100 to have the assembly use a base p/n and the machined part use a base p/n plus a suffix (-dash)?", is YES.

Thoughts and comments from everyone will be greatly appreciated.

Thanks, Ron

 

[looslib]

I would agree that a base number for the assembly and -dash numbers for components is acceptable.
We do that for 2 different scenarios.
The first is an inseparable assembly, weldment. The details are are all assigned dash numbers of the final weldment assembly and detail on sheets in the same drawing.
The second is a unique sub-assembly. A pipe with welded flanges on the ends that is usually only used by the assembly itself. While there is potential reuse of this pipe assembly, it is rare, and the additional usage may have a common part number or a unique one.


"Wildfires are dangerous, hard to control, and economically catastrophic."

Ben Loosli

 

[swertel]

I concur with your YES answer.
But, I urge you to, somewhere on your drawing, usually just above your title block, a notation that states "PART NUMBER: ABC1234"
(Forgive me for not giving the exact AMSE reference that illustrates how/why to do that.)

The main reason I urge you to add the extra identification is because otherwise people will assume that ABC1234 only applies to the drawing, not the assembly. So, while each component within your assembly (ABC1234-X) obviously has an ID, the assembly itself seems vacant of one.

--Scott
www.wertel.pro

 

[James7443]

Scott,

Actually I was planning on doing just that by placing the part number just under the isometric view.

Thanks for the reply.

Ron

 

[jassco]

Hi, Ron:

Parts and assemblies are just items defined by their associated print(s). You can use any number, character,or a combination of them as long as they are not duplicated. If you try to use dash number for your parts, you actually try to build some intelligence into your numbering systems. This intelligent system may does more harm than good as there are redundant relationship between parts and assemblies. A true relationship between parts and their assembly is BOM. Anything else is redundant.

My short answer to your question is yes, you can use them. But my question to you is what do you do when more than one assembly uses a same component.

Best regards,

Alex