Salt spray per Mil-DTL-5541 coupons required 5 or 10

We use one process to chemically convert aluminum. Based on how long the aluminum stays in the chemical conversion chemical determines how thick the coating is when it comes to being able to pass the electrical resistance testing for a class 3 coating. The salt spray test requirements for either class 1A or class 3 is the same. If we coat our test panels to a class 3 and pass the electrical resistance (pre and post saltspray) and pass the salt spray test it is logical to assume that a class 1 conversion coating would pass the saltspray testing as well. My question is if I label my 5 test panels as class 3/1A would that cover the mil spec 5541F section 4.2.1 or do I need to supply 10 coupons total... 5 for class 1A and 5 for class 3.... which is what the spec seems to read... logically it makes sense that I only need 5 but what would a NADCAP auditor conclude?

What does your customer requires... you might be correct but talk to your customers and let them know that you meet the requirements - if there is anything else that they require.

This process is done for our internal parts that make up an assembly that we sell so we are really our own customer in regards to the chem conversion on the part. But would an auditor agree with what I am doing?

robanbieber said:

This process is done for our internal parts that make up an assembly that we sell so we are really our own customer in regards to the chem conversion on the part. But would an auditor agree with what I am doing?

Click to expand...

Most auditors would follow and so would the customer would go to your strictest interpretation - leave no doubt..... Now if it is an expensive process and you are following the minimum requirements - remember all the auditor is looking for compliance and if you could meet the standard and your procedure - should not be an issue.

Bear in mind that auditors have a lot of opinions so... one would agree one year the same auditor would disagree.

But if you still have concern - call them up for a clear interpretation - NADCAP - call the technical adviser for interpretation.