I wouldn't worry about the rev. no., the problem is the difference between 2484 & 2485. IMHO, the 2484 coating is much inferior -- it has less adhesion & under acidic exposure can give off noxious gas such as H
2Se.
The 2484 coating that I am familiar with is CuSe (and/or Cu
2Se) formed by immersion plating of Cu onto Fe in the presence of selenous acid. It is not an oxide, so if your P.O. specified 'Black Oxide,' and especially if you have a wear application, you should force a re-work at no charge.
The 2485 coating, 'hot black oxide,' is formed by oxidizing the surface in a concentrated, alkaline, oxidizing solution at ~290
oF, and is extremely adherent.
From
"AMS2485 : Coating, Black Oxide 10-22-2002 Standard
This specification covers the engineering requirements for producing black oxide coatings on parts and the properties of such coatings.
This coating has been used typically to improve the anti-chafing and anti-friction properties of carbon and low-alloy steel parts, particularly sliding or bearing surfaces, by providing a finish coating which will retain an oil film, but usage is not limited to such applications.
AMS2484 : Blackening Solution for Steel Touch-Up Method 07-01-2000 Standard
This specification covers the requirements for an inorganic blackening solution for steel, applied at room temperature.
This blackening solution has been used typically for touch-up of black oxide surface finish in cases where the coating has been removed."
The same water-displacing oils and waxes can be applied to the latter finish, so it could be used for appearance sake & corrosion prevention in non-friction applications.