1.1 This specification covers requirements for electrolytically formed porous oxide coatings on aluminum and aluminum alloy parts in which appearance, abrasion resistance, electrical properties, and protection against corrosion are important. Nonporous, barrier layer anodic coatings used for electrical capacitors are not covered. Seven types of coatings as shown in Table 1 are provided. Definitions and typical examples of service conditions are provided in Appendix X1.
Note 1—It is recognized that uses exist in which modifications of the coatings covered by this specification may be required. In such cases the particular properties desired by the purchaser should be the subject of agreement between the purchaser and the manufacturer.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
TABLE 1 Anodic Coatings Descriptions
Note—Hard coatings may vary in thickness from 12 μm to more than 100 μm. If the thickness of Type A is not specified, it shall be 50 μm min. Type A coatings will not be sealed unless so specified.
| Type | Coating (Industry) Description | Minimum Film Thickness (μm) |
| A | Engineering Hard Coat | 50 |
| B | Architectural Class I | 18 |
| C | Architectural Class II | 10 |
| D | Automotive—Exterior | 8 |
| E | Interior—Moderate Abrasion | 5.0 |
| F | Interior—Limited Abrasion | 3 |
| G | Chromic Acid | 1 |