MIL-DTL-13924E Specification Guide
This specification covers black oxide coatings applied to ferrous metals (carbon, low alloy, and corrosion resistant steels, and wrought iron). Black oxide coatings, with or without a supplementary preservative treatment (see 3.11), may be used where a black surface is required. Only very limited corrosion protection, under mildly corrosive conditions, is obtained as a result of black oxide coating (see 6.1). Black coatings are included in this specification with limitations as noted in 1.2. Unless contraindicated by contract, chrome-free finishes should be used in place of finishes containing hexavalent chromium, provided all performance criteria herein has been met and documented as OQE.