PHOSPHATE COATINGS

Phosphate coatings consist of crystalline, non-reflective, water insoluble metal phosphates that are very adherent to the base metal. They can be associated in three main categories:

        ZINC PHOSPHATE

• Heavy zinc phosphate that has the ability to retain rust inhibiting oils, preservatives, or other specified finishes.
• MIL-DTL-16232, Type Z
  
  
• Lighter zinc phosphate has a smoother crystal structure and is normally not oiled as it is used as a base for paint.
• DOD-DTL-16232, Type Z
  
  
• TT-C-490, Various Types and Methods
  
  
• DOD-P-50002, Type Z
  
  
• MANGANESE PHOSPHATE
• Chosen for wear resistance and the ability to retain oils.
• DOD-DTL-16232, Type M
• DOD-P-50002, Type M
  
   
• IRON PHOSPHATE
• Utilized as a paint or powder coating base.
• There are numerous proprietary phosphate baths within each group that meet specific part requirements.