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"Status of non-hex chromates on the QPL for MIL-C-5541?"


Hello everyone,

I, and I assume most everyone else too, have been watching and waiting for a non-hex conversion coating to get listed on the QPL for Mil-C-5541 [link is to free spec at Defense Logistics Agency, dla.mil]. So far the Mil-DTL-81706 [link is to free spec at Defense Logistics Agency, dla.mil] standard has been amended to allow for such coating to be listed, but none have actually made it on the QPL yet (at least, according to the ASSIST website).

Does anyone know if there are any that are close? Or, even better, if the board in charge of the standard are considering moving to just performance based requirements and ditching the QPL?

Thanks for any info,

Jim Gorsich
Accurate Anodizing Inc.
supporting advertiser
Compton, California, USA
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The answer is yes very close but that is as far as what I can say now.

drew nosti
Drew Nosti, CEF
Anodize USA
supporting advertiser
Ladson, South Carolina


I know that at least 2 mfg's of trivalent chromate products have been submitted for approval, but who knows how long before the QPL is updated.
We are processing to ASTM B921 [affil. link to spec at Techstreet] in the absence of any other standard.
Hope that helps!

Bill Grayson
- San Jose, California


Thanks to both of you, the info helps. I hadn't thought about just certifying to ASTM B921, I'll have to look into that.

And I'm glad to hear that Drew is the process of getting the non-hex-chrome finish he often talks about on the list, it looks like one of the more interesting hex-replacements out there...

Again, thanks.

Jim Gorsich
Accurate Anodizing Inc.
supporting advertiser
Compton, California, USA
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You may ask why does a decorative plater need chromating solutions. Well we have a European customer that is requiring all contact marks be covered with a primer. Since primers don't stick well to bare aluminum we needed a chromate conversion coat prior to the primer. I found a trivalent chromate conversion coat which, according to the supplier was developed by the U.S. Navy, marketed through them and has been included on the QPL for MIL-C-5541, Class 1a and Class 3.

Tim Hamlett
Tim Hamlett, CEF
- West Palm Beach, Florida, USA


I think it will be correct to say that some hexval. chrome-free processes and complete chrome-free processes can meet requirements of MIL-C-5541. As far as I know none chrome-free process is mentioned in QPL.
I would wish to be mistaken in this fact.

Ilya Ostrovsky


Quickly, I have also been looking into the use of the tri-chrome process and so far we have had positive results.

My biggest concern is how can we be sure that the parts being coated are compliant. Are the coating processes certifiable so that we can receive an approval document from our suppliers stating their compliance?

Luke Anderson
- State College, Pennsylvania, USA


To meet the requirements of MIL-C-5541E you must use materials listed on QPL-81706. The latest (as of 2005) is Revision 16, Amendment 2. No non-hex products are on this list.

Chris Jurey, Past-President IHAA
Luke Engineering & Mfg. Co. Inc.
supporting advertiser
Wadsworth, Ohio
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The trivalent replacement for a hex product that the Navy developed works very well and meets ROHS,WEEE,ELV Directives as well as passing the QPL testing, subject to the end of the shelf life test. The Navy licensed 4 companies to market TCP.

Bill Campbell
- El Dorado Hills, California


The US Navy (NAVAIR) has licensed Metalast, SurTec, Henkel and Luster-On to make, use or sell its TCP in North America (Canada, Mexico and US). SurTec is the exclusive licensee for foreign markets.

Craig Matzdorf
U.S. Navy (NAVAIR) - Patuxent River, Maryland, USA

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