plating, anodizing, & finishing Q&As since 1989
Does Mil-DTL-5541, type II class 1 A imply trivalent chromate?
November 23, 2011
Does MIl-DTL-5541F type II class 1 A imply that trivalent chromate is being used?Jim Plenzler
- Plymouth, Michigan
January 5, 2012
"Type II Compositions containing no hexavalent chromium."
"6.1.1 Class 1A. Class 1A chemical conversion coatings are intended to provide corrosion prevention on unpainted items as well as improve adhesion of paint finish systems on aluminum and aluminum alloys. Coatings of this type may be used, for example, on tanks, tubing, and component structures where paint finishes are not required for interior surfaces but are required for the exterior surfaces."
I think they are shooting for being inclusive of trivalent chromate without limiting people to it in case something better comes along in six months. Anything that's not hex chrome and meets Class 1A.
Stellar Solutions, Inc.