RoHS Compliant MIL-C-5541: Positive Hex-Free Update

Summary for rohs compliant mil-c-5541 Discussion

RoHS compliant Mil-C-5541 is the core issue in this thread: Jim Roberson asked for a class 3, electrically conductive Chem Film equivalent to MIL-C-5541 that would avoid hexavalent chromium. In the answer, it was noted that at the time of the question there was no compliant substitute because the then-current MIL-C-5541 required hexavalent chromium. However, the reply adds that a later revision, MIL-C-5541F, permits qualified hex-free products. The answer specifically points to the NAVAIR-developed TCP process, which was licensed to four suppliers believed to be on the QPL: Henkel, Luster-On, Metalast, and Surtec. The practical takeaway is that the answer depends on the revision and qualification status, and that hex-free options became available only after the newer specification revision.