Example: To obtain an etched, matte surface protected by an anodic treatment suitable for unmaintained exterior exposure, the designation would be as follows:
AA — Aluminum Association
C12 — Chemical Treatment (inhibited alkaline coating)
C22 — Medium Matte etched surface
A41 — Clear anodic coating at least 0.7 mil thick
The designation would read: AA-C12-C22-A41
Mechanical Finishes
Type of Finish
AA Designation
Description
Examples of Methods of Finishing
As Fabricated
M10
Unspecified
M11
Specular, as fabricated
M12
Nonspecular, as fabricated
M1X
Other
To be specified
Buffed
M20
Unspecified
M21
Smooth Specular
Polished with aluminum oxide compound. Grits coarser than 320; final polishing with a 320 grit using peripheral wheel speed of 6,000 fpm. Polishing followed by buffing using aluminum oxide buffing compound and peripheral wheel speed of 7,000 fpm
M22
Specular
Buffed with aluminum oxide compound using peripheral wheel speed of 7,000 fpm.
M2X
Other
To be specified
Directional Textured
M30
Unspecified
M31
Fine Satin
Wheel or belt polished with aluminum oxide grit of 320 to 400 size; peripheral wheel speed of 6,000 fpm.
M32
Medium Satin
Wheel or belt polished with aluminum oxide grit of 180 to 220 size; peripheral wheel speed of 6,000 fpm.
M33
Coarse Satin
Wheel or belt polished with aluminum oxide grit of 80 to 100 size; peripheral wheel speed of 6,000 fpm.
M34
Hand-Rubbed
Hand-rubbed with stainless steel wool lubricated with neutral soap solution. Final rubbing with a No. 00 steel wool.
M35
Brushed
Several varieties of directional finish with parallel scratch lines may be produced by using power-driven stainless steel wire-wheel brushes, brushed-backed sander heads, abrasive-impregnated foam nylon discs or abrasive cloth wheels.
M3X
Other
To be specified
Non-Directional Textured
M40
Unspecified
M41
Extra-fine Matte
Air-blasted with finer than 200-mesh washed silica or aluminum oxide. Air pressure 45 lb. gun 8-12 in. at 90 º angle.
M42
Fine Matte
Air-blasted with finer than 100- to 200-mesh silica sand if darkening is not a problem; otherwise aluminum oxide type abrasive. Air pressure 30 to 90 lb. (depending upon thickness of material); gun distance 1 foot from work at angle of 60 º to 90º .
M43
Medium Matte
Air-blasted with finer than 40- to 50-mesh silica sand if darkening is not a problem; otherwise aluminum oxide type abrasive. Air pressure 30 to 90 lb. (depending upon thickness of material); gun distance 1 foot from work at angle of 60 º to 90º .
M44
Coarse Matte
Air-blasted with finer than 16- to 20-mesh silica sand if darkening is not a problem; otherwise aluminum oxide type abrasive. Air pressure 30 to 90 lb. (depending upon thickness of material); gun distance 1 foot from work at angle of 60 º to 90º .
Chemical Finishes
Type of Finish
AA Designation
Description
Examples of Methods of Finishing
Nonetched
Cleaned
C10
Unspecified
C11
Degreased
Organic solvent treated
C12
Inhibited-chemical cleaned
Inhibited chemical type cleaner used
C1X
Other
To be specified
Etched
C20
Unspecified
C21
Fine Matte
Trisodium phosphate, 3-6 oz. per gallon used at 140-160 ºF for 3 to 5 minutes
C22
Medium Matte
Sodium hydroxide, 4-6 oz. per gallon used at 140-150 ºF for 5 minutes.
C23
Coarse Matte
Sodium fluoride, 1-1/2 oz., plus sodium hydroxide, 4-6 oz. per gallon used at 140-150 ºF for 5 minutes.
C2X
Other
To be specified
Brightened
C30
Unspecified
C31
Highly Specular
Chemical bright dip solution of the proprietary phosphoric-nitric acid type used, or proprietary electrobrightening or electropolishing treatment.
C32
Diffuse bright
Etched finish C22 followed by brightened finish C31
C3X
Other
To be specified
Anodic Coatings
Type of Finish
AA Designation
Description
Examples of Methods of Finishing
Protective & Decorative (coatings less than 0.4 mil thick)
A21
Clear (natural) coating
Coating thickness to be specified, 15% H2SO4, used at 70ºF +/- 2ºF, at 12 amp per sq. ft.
A22
Coating with integral color
Coating thickness to be specified. Color dependent on alloy and processing methods.
A23
Coating with impregnated color
Coating thickness to be specified, 15% H2SO4, used at 70ºF +/- 2ºF, at 12 amp per sq. ft. followed by dyeing with organic or inorganic colors.
A2X
Other
To be specified
Architectural Class 11 (0.4 to 0.7 mil coating)
A31
Clear (natural) coating
15% H2SO4, used at 70ºF +/- 2ºF, at 12 amp per sq. ft. for 30 minutes, or equivalent.
A32
Coating with integral color
Color dependent on alloy and anodic process
A33
Coating with impregnated color
15% H2SO4, used at 70ºF +/- 2ºF, at 12 amp per sq. ft. for 30 minutes, or equivalent followed by dyeing with organic or inorganic colors.
A3X
Other
To be specified
Architectural Class 1 (0.7 mil and greater anodic coating)
A41
Clear (natural) coating
15% H2SO4, used at 70ºF +/- 2ºF, at 12 amp per sq. ft. for 60 minutes, or equivalent.
A42
Coating with integral color
Color dependent on alloy and anodic process. May include Duranodic and certain architectural colors
A43
Coating with impregnated color
15% H2SO4, used at 70ºF +/- 2ºF, at 12 amp per sq. ft. for 60 minutes, or equivalent followed by dyeing with organic or inorganic colors.
