Guide to Anodic Coating Designations
Aluminum Association Anodic Coating Designations
The chemical finishes and comparative anodic coatings chart provides guidelines that match processing and required anodic film thickness with customer needs.
Mechanical Finishes for Aluminum
Mechanical finishes are less common than they once were because they are labor intensive and difficult to apply.
Most aluminum is specified with “M10” which means “Unspecified, As Fabricated.”
However, some applications call for specular buffing (M22) or directional sanding (M32).
Contact SAF for more information about brushed, buffed and polished aluminum finishes.
Chemical Finishes for Aluminum
Type of Finish | Alcoa Designation | Aluminum Association Designations | Description | Example methods of finishes (Not Definitive Techniques) |
Non Etched Cleaned |
C-10 C-11 C-12 C-1X |
Unspecified Degreased Inhibited Chemical Cleaned Other |
Organic solvent treated Inhibited chemical type Cleaner used To be specified |
|
Etched | R1 R2 R3 |
C-20 C-21C-22 C-23 C2X |
Unspecified Fine MatteMedium Matte Course Matte Other |
Trisodium phosphate, 3-6 oz / gal. used at 140-160 deg F for 5 min. Sodium hydroxide, 4-6 of. / gal. used at 140-160 deg F for 5 min. Sodium Fluoride. 1 1/2 oz. plus sodium hydroxide 4-6 oz. / gal. used at 140-160 deg F for 5 min. To be specified |
Brightened | R5-Bright Dip* EB10, EB30 Bright Dip |
C-30 C-31 C-32 C3X |
Unspecified Highly Specular Diffuse bright Other |
Chemical bright dip solution of the proprietary phosphoric nitric acid type used or proprietary electrobrightening Etched finish C22 followed by brightened finish C31 To be specified |
*Trade Name of Aluminum Company of America (Alcoa)
Comparative Anodic Coating Designation
Film Thickness | Alcoa Designation | Aluminum Association Designations | Descriptions | Type of Finish | Film Thickness |
0.0001″ | Alumilite 200 .00015 minimum film thickness | A21 | Clear (natural) Coating | Protective and decorative (coatings less than 0.4 mils thick) Thickness to be specified by customer) | 2.56 uM |
0.0001″ | n/a | A22 | Coating with intergal color (discontinued by SAF) | “ | 2.56 uM |
0.0001″ | n/a | A23 | Coating with impregnated color. | “ | 2.56 uM |
0.0001″ | n/a | A24 | Coating with electrolytically deposited color. | “ | 2.56 uM |
0.0002″ | Alumilite 201 .0002 minimum film thickness | A212 | Clear (natural) coating |
“ | 5.13 uM |
0.0003″ | Alumilite 202 .0003 minimum film thickness | A213 | “ | “ | 7.69 uM |
0.00036″ | Alumilite 203 .00036 minimum film thickness | A213 | “ | “ | 9.23 uM |
0.0004″ | Alumilite 204 .0004 minimum film thickness | A31 | Clear (natural) coating | Architectural Class II 10 to 18 uM (.4 mil to 0.7 mil) coating thickness. | 10.26 uM |
0.0004″ | n/a | A32 | Coating with integral color (discontinued by SAF) | “ | 10.26 uM |
0.0004″ | n/a | A33 | Coating with impregnated color | “ | 10.26 uM |
0.0004″ | n/a | A34 | Coating with electrolytically deposited color. | “ | 10.26 uM |
0.0007″ | Alumilite 215 .0007″ minimum film thickness | A41 | Clear (natural) coating | Architectural Class I 18uM (0.7 mils) and greater anodic coating. | 18.0 uM |
0.0007″ | Duranodic (311, 312, 313, 335) (discontinued by SAF) | A42 | Shades of bronze & black | “ | 18.0 uM |
0.0007″ | Dyes | A43 | Nearly unlimited color selection. | “ | 18.0 uM |
0.0007″ | 2-Step | A44 | Shades of bronze & black | “ | 18.0 uM |