Anodic Coating Designations

ALUMINUM ASSOCIATION

Anodic Coating Designations

The chemical finishes and comparative anodic coatings chart are designed as guidelines that match processing and required anodic film thickness with customer needs.

Mechanical Finishes

Mechanical finshes are less common than they once were because 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 finishes.

Chemical Finishes

Type of Finish Alcoa Designation Alum. Assn. Designations Description Examples of 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 Ffor 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 electrobrighteningEtched 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