Part Numbers – Dash vs. Rev (Frank Watts' Engineering Documentation Control Handbook)

[tKc74]

Hey folks,

I've been scratching my head over Frank Watts' Engineering Documentation Control Handbook 4th Ed., particularly the use of a "dash" in Part Numbers. Seems a lot like just putting a Rev in there, which Watts strictly says don't do.

For instance:

PN 123456-01
(some non-interchangeable change occurs)
PN 123456-02

This is the exact procedure to follow, as outlined on P.66 of Engineering Documentation Control Handbook 4th Ed.

Note: For those who use the tab/dash technique suggested in this book,
when non-interchangeable changes occur, the item drawing will be revised
and the rev of the document increased in order to increase the tab to the
next number (01 to 02 for example).

Now, how is this different from up-revving like this:

PN 123456-R1
(some non-interchangeable change occurs)
PN 123456-R2

To me, they look the same. But Watts is adamant about no Rev in the Part Number. Am I missing something about the "Document Number" (the digits before the dash)? In both cases, it's DWG#: 123456.

Each PN is in its assembly parts lists, yet including the Part Revision in the parts list is a strict no-go. I can't help but notice that the dash method essentially achieves the same outcome.

I'm missing something, please help

Cheers,

“If the women don't find you handsome, they should at least find you handy.” - Red Green

 

[cowski]

It's been a while since I read that section and my copy is not close to hand, but IIRC, 123456-01 is the part number and it would have a revision: 123456-01 rev C, for instance. When the part is changed and it is no longer compatible with the previous revision, it gets a new part number, 123456-02 rev A.

 

[CWB1]

Prefix - Base - Suffix
Internal Usage - Base - Revision

At a minimum, every part must be marked with a base p/n and revision separated by a dash for identification purposes. There's no need to write "rev" on a part, the dash/suffix is the revision level.

Some companies love to code info about the product/part owner, product line, or other nonsense into the prefix. Personally I find it a useless, counterproductive complication. Anybody that needs the details usually has ready access to PLM or other means of finding them. Meanwhile, a p/n that should be easily rememberable and identifiable on the shop floor isnt.