Can you deviate from a mil standard?

[Spoolx]

Hi all,
I ran across something today and wanted to get other engineers opinions.

I design products for a company and we routinely use mil specs to identify process parameters for our products.

Recently, I released a drawing that said process per the anodize mil-spec-xxx.xxx and below it I identified a thickness that does not fall completely within the range of the mil-spec

More specifically I said process per mil-spec -xxx.xx, and apply a coating thickness of .0004-.0008. However, the mil spec recommends a minimum of .0005.

In our business we use the anodize primarily for aluminum protection and color, the thickness range was recommended by the coating business who applies this anodize per the mil spec all day every day. When I say protection I simply mean no oxidation, it is a hand held device that does not mate with anything.

I originally thought it was no problem but I am starting to second guess myself. The mil-spec provides tons of information, and we deviate from one small portion of it to fit our needs, but we aren't military.I feel like our drawings are the final say, so if we state process per the mil-spec but then below it we have a small deviation than its legit. Obviously we want 99% of the process to be followed so it wouldn't make sense in my opinion to do it any other way.

What is everyone's take on it?

 

[Grinkle]

Be clear in the drawing, and note any exceptions to the spec in the same place you call out the spec. EG - Anodize per mil-spec-etc with the below approved exception etc.

 

[Spoolx]

I didnt put exactly like you suggest however I did put
Anodize per MIL-xxx-xxx
Anodize Thickness .0004"-.0008"

Thanks for the reply

 

[OldYat47]

I agree with Grinkle. But I have to ask, if you're using the mil spec and would be happy with thicknesses up to 0.0008", why would you include the complication of an 0.0001" less-than-spec thickness?

 

[Grinkle]

OldYat47 - the OP said it was recommended by the vendor, its probably to reduce scrap.

 

[OldYat47]

Hmmm. Looks like the vendor is trying to stay very close to the minimum thickness. Interesting.

 

[Spoolx]

We did it primarily for the color, we are using a very light turquoise and when you go up even a few tenths in thickness it changes the color dramatically. Our components are anodized primarily for cosmetic preference and marketing wanted this color.

Of course we could have done .0005-.0008 but we were concerned with the anodized passing supplier validation so we gave him an extra .0001 on the bottom end.

 

[Spoolx]

Thanks for the reply guys

 

[marcusl]

If you are delivering a product for which the customer specifies a mil std, then you must follow it exactly or else apply for a waiver from the. customer.

 

[Spoolx]

We are the designers and owner of the design for a product we own and manufacture