I have a loaded question: Most of our product is anodized as the finished. We do 90% of our machining in house. Currently, we're having an issue with the 10% outside suppliers not understanding how to read a white or black drawing (white=machining, black=finished product/part). We have notes on our indicating ALL DIMENSIONS APPLY BEFORE ANODIZING. Because of the defects and NCR's, we decided to flag all critical dimensions on the drawings with mfg. dim data and anodizing dim data. My question to you, is there an easier way of doing this?

I might add, we did come up with system where we had black and white drawings, but this just clogged our checking and drafting departments with a double work load.

Joel

Can you post a few sections of one of these prints? I have not seen a print with before and after anodize. Most of the time a note or a thickness spec for the anodize is called out in a note or the title block.

I have not even heard of a black/white print, most prints I see might have a solid line for casting/forging with a dashed line called a phantom line for machined surface, or a feature thru the casting/forging.

but is friday so maybe I not thinking clear........:confused::rolleyes:

I have a loaded question: Most of our product is anodized as the finished. We do 90% of our machining in house. Currently, we're having an issue with the 10% outside suppliers not understanding how to read a white or black drawing (white=machining, black=finished product/part). We have notes on our indicating ALL DIMENSIONS APPLY BEFORE ANODIZING. Because of the defects and NCR's, we decided to flag all critical dimensions on the drawings with mfg. dim data and anodizing dim data. My question to you, is there an easier way of doing this?

I might add, we did come up with system where we had black and white drawings, but this just clogged our checking and drafting departments with a double work load.

Joel

Hi Joel and welcome to the Cove,

I am not familiar with the term "white" or "black" drawing. Is this something that is unique to your industry?

Your data with regards to anodizing - what are you trying to control? The thickness of the anodonic coating? Are you asking your plater to hold a certain dimension after plating? Or a particlular plating thickness?

The plating process is not exact, meaning that you do not get the exact thickness on all surfaces. Depending on the configuration of your part, you could have excessive build-up in some areas. Most parts tend to show thicker plating on edges and holes - and threads are a whole different subject.

In most of the drawings that I have seen, they usually reflect that the dimensions apply after plating (unless otherwise specified). This must be specific to your product/service.

I have a loaded question: Most of our product is anodized as the finished. We do 90% of our machining in house. Currently, we're having an issue with the 10% outside suppliers not understanding how to read a white or black drawing (white=machining, black=finished product/part). We have notes on our indicating ALL DIMENSIONS APPLY BEFORE ANODIZING. Because of the defects and NCR's, we decided to flag all critical dimensions on the drawings with mfg. dim data and anodizing dim data. My question to you, is there an easier way of doing this?

I might add, we did come up with system where we had black and white drawings, but this just clogged our checking and drafting departments with a double work load.

Joel

First, contrary to a few of the responses so far, anodizing is not a "plating" process. No material is transferred to the part as in the case of zinc or chrome electroplating (for example). Anodizing involves an electrochemical action that creates a layer of oxide on the part.

It appears that you may be creating confusion for a few suppliers who aren't paying attention. In general, there should be no need to create multiple drawings; all you need to do is create a drawing for the finished part, specify the type of anodizing required (and the relevant standard) and specify that dimensions apply after anodizing. It's then up to the supplier to determine pre-anodizing dimensions and to control the anodizing process such that final dimensioning requirements are met.

Thanks for the replys. Basically, we have a MAJOR problem with our machining suppliers not reading the print - thus, the machine to finish dimensions. Unfortunately, we can not replace them. Several do unique processes for us or have direct ties "elsewhere." We have tried to train, work with them on how to read our drawings etc.

Regardless, what I was looking for, was if someone had some method on how to list both dimensions, before and after, anodozing on the same drawing - only for critical dimensions.

With the non-conformances being generated, we're losing our schedules for production.

Thanks
Joel

Regardless, what I was looking for, was if someone had some method on how to list both dimensions, before and after, anodozing on the same drawing - only for critical dimensions.


Can you create a table on your prints, indicating the before and after dimensions? Give the critical feature dimensions an alpha designator, then show your before and after dimensions for that alpha designator in the table.

Thanks for the replys. Basically, we have a MAJOR problem with our machining suppliers not reading the print - thus, the machine to finish dimensions. Unfortunately, we can not replace them. Several do unique processes for us or have direct ties "elsewhere." We have tried to train, work with them on how to read our drawings etc.

Regardless, what I was looking for, was if someone had some method on how to list both dimensions, before and after, anodozing on the same drawing - only for critical dimensions.

With the non-conformances being generated, we're losing our schedules for production.

Thanks
Joel

We don't use outside machine shops but what we do internally is show the finished specification with a note "Anodize <color> Per Mil-A-8625 Type X, Class X, .0003-.0004 total thickness (just to pick numbers)"
This tells our set up guys to set the machine to, say, .001 over nominal on an ID or .001 under nominal on an OD to compensate for the anodizing and sealer.
Then when the part comes back from the anodizer QC checks to the drawing dimension.

If we were using an outside machinist... I'd probably just give them a drawing with pre-anodizing dimensions as that's all they should have to care about.
Then when the part comes back in from the anodizer I'd have a finished good drawing for incoming inspection at our facility.

And while Jim is technically correct about anodizing, I find that most people use "plater" and "anodizer" interchangeably. All our suppliers do both and "plater" is just easier off the tongue. :D

Surefire, to me I would see your company as the problem, your making up some new kind of print???? Why reinvent the wheel?

And while Jim is technically correct about anodizing, I find that most people use "plater" and "anodizer" interchangeably. All our suppliers do both and "plater" is just easier off the tongue. :D
I agree. I was only pointing out that anodizing is a fundamentally different process than plating, and while it's common to refer to anodizers as platers, confusion may be caused by referring to anodized parts as plated.

As to the OP's predicament, it seems to me that his company's strategy with regard to engineering drawings is probably contributing to the problem. The standard way of doing things--the way that machining houses are used to seeing things specified--is as I described in my earlier post. You give them the finishing spec and finished part dimensions, and let them take care of the rest. If they can't do this, nothing that you do with your documentation is going to help, and it could make things worse.

If they can't do this, nothing that you do with your documentation is going to help, and it could make things worse.

I agree 100% and may go back to enforcing dimensions apply after anodizing...

Thanks

If they can't do this, nothing that you do with your documentation is going to help, and it could make things worse.

I agree 100% and may go back to enforcing dimensions apply after anodizing...

ThanksJust an additional thought:
Many folks think "Contract Review" is only for the supplier to consider. Actually, BOTH customer and supplier need to assure they are clear on what the final result should be.

Many customers get so involved in "micromanaging" the processes used by a supplier through notes on the purchase order and engineering drawing, they paint themselves into a corner by not learning exactly what the capability and capacity of the supplier is prior to granting the contract.

Thanks for the replys. Basically, we have a MAJOR problem with our machining suppliers not reading the print - thus, the machine to finish dimensions. Unfortunately, we can not replace them. Several do unique processes for us or have direct ties "elsewhere." We have tried to train, work with them on how to read our drawings etc.

Regardless, what I was looking for, was if someone had some method on how to list both dimensions, before and after, anodozing on the same drawing - only for critical dimensions.

With the non-conformances being generated, we're losing our schedules for production.

Thanks
JoelThis goes especially for those suppliers who are somehow "blessed" by a higher authority with the right to get a contract despite a deficiency in either capability or capacity. These are precisely the folks with whom additional understanding might be necessary.

As one example of the "special understanding," I recall a customer more than 20 years ago showing me a set of specially created go/no go gages he had made for use by a "sister company" which somehow seemed incapable of using measuring instruments to inspect parts prior to shipment to his assembly plant.

"That's nice," I said. "So!?"

"I need your company to devise some more gages for these other parts the bosses at HQ have also assigned to the same sister company! You need to work with my designers to figure out the critical dimensions that we can control with gages."

It was wasted breath pointing out the net cost in place of parts from the sister company was much higher than if he bought them from a competent supplier. He knew that, but was powerless to act against the wishes of his superiors at HQ and tried to make the best of a bad situation with the gages.

You have my sympathy, Joel.:frust:

Thanks for the replys. Basically, we have a MAJOR problem with our machining suppliers not reading the print - thus, the machine to finish dimensions. Unfortunately, we can not replace them. Several do unique processes for us or have direct ties "elsewhere." We have tried to train, work with them on how to read our drawings etc.

Regardless, what I was looking for, was if someone had some method on how to list both dimensions, before and after, anodozing on the same drawing - only for critical dimensions.

With the non-conformances being generated, we're losing our schedules for production.

Thanks
Joel

Joel,
I deal with Sub-Suppliers regularly, Our company developed a secondary Instruction/Inspection Form and then attached this to a finished print, we dimensioned their process to allow for anodizing, plating, etc. If you would like I can email you an example.