Anodized Aluminum Finishes

requirements, explanations, and reference materials

As reported in AAC's Technical Bulletin #2-13 the information presented here is intended to be a useful guide for anyone seeking requirements, explanations, and reference materials when specifying finishes for anodized aluminum. The novice will gain insightful background information and guidance, while the expert may use this as a quick reference.

Primary Designation Systems
In addition to the commonly used designation systems listed below, many proprietary specifications are written for industry-specific or individual company applications. The four main designation systems used for specifying aluminum finishes are as follows:

• Aluminum Association (AA) Designation System for Aluminum Finishes (Publication #45)
• Alcoa's Alumilite Finishes nomenclature
• Military specification MIL-A-8625
• Automotive Standard AAC 1119

Note: The American Manufacturers Association (AAMA) has adopted the AA designation system in its Voluntary Standards for Anodized Architectural Aluminum.

Type of Finish to be Specified
There are a number of factors to consider when specifying anodic finishes. Different finishing processes may be specified depending on the use of application of the final product. Some of the factors to be considered are:

• Appearance: Bright, matte, colored, brushed, other
• Environment of use:
  • Interior (architectural, commercial, decorative, other)
  • Exterior (architectural, marine)
  • Industrial/Automotive (corrosive or noncorrosive application, resistance to wear or abrasion, other)
  • Aerospace (corrosive resistance, dielectric, emissivity, fatigue strength, other).

Criteria for Specifying Anodized Aluminum
When specifying anodized aluminum products, the following specific criteria should be addressed:

• Alloy and temper of aluminum to be used
• Mechanical finish, if any, required
• Chemical finish in preparation for anodizing
• Anodic oxide requirements