AMS 2644 Revision G: Key Changes and Updates

AMS 2644 Revision G: Key Changes and Updates

On April 8, 2019 AMS 2644G1 was published, replacing the 2013 revision F.  This revision was completed as part of a standard review cycle, and to address changes in the industry and shortcomings of the previous revision. 

Water-Based Penetrants Get Their Own Classification: Method A(W) 

One significant change in Revision G is the inclusion of a new class of penetrants, Method A(W).  Method A(W) was created to distinguish between Method A penetrants that are water-based, and those that are oil or surfactant based.  Previously, all Method A materials were lumped together, regardless of their chemical composition.  This change was made to address the increased interest in the market for products that are water-based.  Method A(W) penetrants are being defined as products that contain 20% or more water.   

Additional changes were made to support the addition of Method A(W) to the specification, including: 

  1. Addition of a flashpoint method that is compatible with aqueous materials. 
  2. A require maximum water content limit of 5% for Method A, B, C, and D penetrants. 


Updates to the Method A Penetrant Qualification Criteria 

The next big update in Revision G is a significant change to the qualification criteria for Method A penetrants.  Since its inception in 1996, the qualification criteria for AMS 2644 have undergone several changes as the lab at Wright-Patterson AFB improved the techniques used to test and approve penetrants.  Although the qualification criteria changed, previously approved products were never required to be retested.  This practice led to a situation where at least some of the penetrants listed on the Qualified Products List (QPL) would not meet the most current qualification criteria. 

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