To part mark, or not to part mark

[mdambros]

I'm not sure if this is the best forum to pose this question, but since it does impact a note on a drawing I'll ask it here.

The company that I am at now is not accustomed to having sheet metal parts physically marked by any methods. I am from a background of commercial, semiconductor, and aerospace. In my experience, we part marked all of our parts either by bag and tag, peen, rubber stamp, engraving, roll marking, etc. I would like to have the parts manufactured for us to be identified by either rubber stamp, or bag and tag, but I am getting a little bit of resistance from others. I believe it is because it is something new to them.

I see the benefits of having a part marked being traceablity and part identification during assembly. Recently we had to similar enclosures going through assembly at the same time, and they were being used on the wrong builds. There was no part marking for easy identification.

What other pros are there to part marking, and what are the cons? What are you guys doing?

Thanks

 

[drawoh]

mdambros,

I am drawing up a bunch of gaskets that look very similar to each other. A note on the drawing requiring part numbers be marked on the gaskets is one of several solutions that will prevent confusion at assembly time. I have in the past, added holes and chamfers to stuff as identification marks.

In general, I would say that marking part numbers is manufacturing's decision. If your parts look unique, and they are stored in numbered part bins, the numbers may not be necessary. Does your warehouse have have access to your drawings? You might not want ink or epoxy markings on your parts, and you might not want them stamped.

Read up on Poka Yoke.

--
JHG

 

[BiPolarMoment]

We laser mark (or engrave) just about everything unless it (and sometimes even if) is a packaged device with an external label. Some of these are required from a regulatory standpoint e.g. CE marking. Typically our warehouse has to piece together a kit based upon a BOM where a description and part number will be listed; having a unique part number is potentially important due to similar looking items and the overall observation skills of the worker pulling the parts (or putting them back in the correct bin).

 

[ctopher]

Depending on the customer or contract, we laser mark whenever we can.

Chris, CSWP
SolidWorks '16
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[MikeHalloran]

Recently we had two similar enclosures going through assembly at the same time, and they were being used on the wrong builds. There was no part marking for easy identification.

Is that experience not a sufficient justification all by itself?

At least scribble a number on with a Sharpie.




Mike Halloran
Pembroke Pines, FL, USA

 

[DiegoLGraves]

We part number stamp all military parts and many parts for some other OEM customers as required by their print or contract. Whenever possible this is done on sheet metal in the cutting program with number stamps and it costs very little to add. A few parts are laser etched if we delivery them unpainted. Other parts are engraved with a peening system or hard stamped at another stage in fabrication. This requires an extra handling so costs more to add. And some items are ink stamped or sharpie marked after paint. For our own product line of electrical enclosures we add serialized labels for UL and labels of the model numbers and build date.

The least expensive method for us is marking with our combination laser and punching machine.

Diego

 

[capnhook]

Consider ink-jet marking systems, also.


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[KENAT]

We have a 'bag & tag' note as default on our drawings - can be overridden if appropriate but gives some minimal level of part identification.

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[swertel]

Bag and tag -- the -37 marking method from the SAE specification. We use it often.
Sorry, memory fails me at the moment to give the actual specification number.

--Scott
www.wertel.pro

 

[ctopher]

Some, not all, customers require the bag and tag method. Some require some type of adhesive label.
Black marker will come off if cleaned with chemicals, or eventually fade.
Besides all methods, my suggestion is to (2D or text) laser mark or engrave, even if additional marking.

Chris, CSWP
SolidWorks '16
ctophers home
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[keyepitts]

Interesting question, we often face this issue also. For those of you that bin your parts, and/or do not tag them individually, how do you handle traceability and tracking the material back to the MTR's?

 

[ctopher]

Without bag/tag, or marking, it's too difficult to track parts. They easily get mixed up.
For aerospace/military, they have to get marked somehow.

Chris, CSWP
SolidWorks '16
ctophers home
SolidWorks Legion

 

[KENAT]

If implementing the ASME Y14.100 rules on when it's a revision V a part number change, and if you've got a good quality system in place, then not being able to tell parts of a given part number apart shouldn't be an issue as they are fully interchangeable.

If traceability is a concern for some reason then yes you need a more robust system.

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