AMS-A-8625 Hardcoat
Anodize Plating Specs

Types of Anodic Coatings Available

• Type 1 – Conventional coatings produced from chromic acid bath
  Purpose: Delivers an electrically non-conductive surface with improved scratch and corrosion resistance. Primarily used in aerospace applications and on castings where components that may undergo flexing due to heat changes or mechanical means
• Type 2 – Sulfuric acid anodizing, conventional coatings produced from sulfuric acid bath
  Purpose: Intended to improve surface corrosion protection under severe service conditions or as a base for paint systems
• Type 2B – Thin sulfuric acid anodizing, for use as non-chromate alternative for Type 1 and 1B coatings
  Purpose: Non-chromate alternative to Type 1 and 1B coatings, where corrosion resistance, paint adhesion, and fatigue resistance are all required
• Type 3 – Hard Anodic Coatings
  Purpose: Provide wear and abrasion resistant surfaces with improved corrosion protection due to greater thickness and weight than the conventional anodic coatings. Reminder: Sealing of Type 3 coatings is not recommended unless corrosion resistance is also a factor, as both wear resistance and fatigue strength can be reduced by sealing

Types of Anodic Coatings Available

• Type 1B – Chromic acid anodizing, low voltage process
• Type 1C – Non-chromic acid anodizing, for use as non-chromate alternative for Type 1 and 1B coating

Classes

• Class 1 – Non-dyed
• Class 2  – Dyed

Acquisition documents should specify the following

• Assembly Anodizing – If an assembly is required, customer MUST provide AOTCO with this information.
• Due to electrolyte entrapment, assembly anodize must be pre-approved by AOTCO on a PART TO PART basis
• Type of anodic coating, title, number and date of this specification
• Class of anodic coating
• Special process operating conditions, if applicable
• Special cleaning and fabrication requirements
• Color and uniformity of Class 2 coatings, if applicable
• Degree of non-uniformity of dyed casting alloys
• Type 3 coating thickness, if applicable
• Coating weight for thickness, (for Type 3) if substituted
• Special sealing requirements
• When applicable, the allowable difference in anodic coating appearance resulting from inherent base metal differences
• Provide the specific location of contact marks if important to the function of the part
• Acceptance criteria for quality conformance inspections
• If paint adhesion testing is required for quality conformance testing and the required paint system