Anodic Coating Designation System
Matching processing & required anodic film thicknesses with customer needs
The chemical finishes and comparative anodic coatings charts are designed as guidelines that match processing and required anodic film thicknesses with customer needs.
Chemical Finishes
| Type of Finish | Continuous Coil Anodizers Assn. | ALCOA Designations | Alum. Assn. Designations | Description | Examples of Methods of Finishing (Not Definitive Techniques) | ||||||||||||
| Non Etched Cleaned | N.P.T. (No Pretreatment) | 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 | Matte Satin | R1 R2 R3 |
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| Brightened | Chem. Brighten Bright-dipped (R5) | R5-Bright Dip* EB10, EB30 R1-R5 Bright Dip |
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Comparative Anodic Coating Designation
Film Thickness | Contiunous Coil Anodizers Assn. Designations | ALCOA Designations | Aluminum Assn. Designations | Description | Type of Finish | |||||||||
.0001 .0002 .0003 .0004 .0005 .0006 .0007 up |
| Alumilite 200 .0015 minimum thickness | A 21 A 22 A 23 A 2X | Clear (natural) coating Coating with integral color Other | Protective & Decorative (coatings less than 0.4 mils thick) (Thickness to be specified by customer) | |||||||||
Architectural Class II .0004 to .0007 Architectural Class I .0007 and up | Alumilite 204 .0004 minimum thickness | A 31 A 32 A 33 A 3X | Same as Above | Architectural Class II (0.4 to 0.7 mil coating) | ||||||||||
Alumilite 214 .0006 minimum film thickness | A 41 | Same as Above | Architectural Class I (0.7 mil and greater anodic coating | |||||||||||
Ordering Specifications
Covering Area (Yield) and Weight per Square Foot
Aluminum Sheet and Foil Gauges
| Decimal Thickness | Pounds Per Square Foot | Square Feet Per Pound | Decimal Thickness | Pounds Per Square Foot | Square Feet Per Pound |
| .002 | .028 | 35.6 | .025 | .352 | 2.85 |
| .003 | .042 | 23.75 | .026 | .364 | 2.74 |
| .004 | .056 | 17.8 | .027 | .379 | 2.64 |
| .005 | .070 | 14.25 | .028 | .392 | 2.55 |
| .006 | .084 | 11.9 | .030 | .422 | 2.38 |
| .007 | .099 | 10.1 | .031 | .435 | 2.30 |
| .008 | .012 | 8.9 | .032 | .450 | 2.23 |
| .009 | .127 | 7.9 | .034 | .478 | 2.09 |
| .010 | .141 | 7.1 | .036 | .505 | 1.98 |
| .011 | .154 | 6.5 | .038 | .533 | 1.88 |
| .012 | .169 | 5.95 | .040 | .563 | 1.78 |
| .013 | .184 | 5.43 | .042 | .590 | 1.69 |
| .014 | .197 | 5.1 | .044 | .617 | 1.62 |
| .015 | .210 | 4.77 | .045 | .631 | 1.59 |
| .016 | .224 | 4.45 | .046 | .645 | 1.55 |
| .018 | .253 | 3.95 | .047 | .660 | 1.52 |
| .019 | .268 | 3.74 | .048 | .674 | 1.48 |
| .020 | .282 | 3.55 | .050 | .704 | 1.42 |
| .022 | .309 | 3.24 | .051 | .719 | 1.39 |
| .023 | .322 | 3.11 | .056 | .785 | 1.27 |
| .024 | .339 | 2.95 | .063 | .889 | 1.125 |
| Based on a density of .0976 pounds per cubicinch (Specific Gravity of 2.70) | |||||
Alloys suitable for anodizing
| 99.99 | Pure Al in sheet, plate or extrusion | Gives highest reflectivity since oxidized surface is free of Si, Fe and Mn which normally obscure polished surface. Easily formable, but low in strength, and expensive. Used primarily for simulated gold finish. Super-purity Al-Mg and Al-Mg-Si alloys give the same brightness; cost is still high, but strength is much improved because of Mg additions. |
| 5005 5252 5257 5357 5457 5557 5657 | Al-Mg alloy in sheet form | Reflectivity is below that of high-purity Al-Mg alloys, but they respond well to anodizing, have good mechanical properties, and are priced for commercial applications like automotive, appliance, and architectural trim. Alloying constituents do not tint coatings. |
| 6063 | Extrusion Alloys | These heat-treatable alloys combine high strength and good response to anodizing. Contain Mg and Si as MgSi. Heat treatment dissolves silicide, improving strength and luster after anodizing. Presence of Si can give coating a gray or brown tint. Alloy 5005 has some Mg for moderate strengthening. |
| 1100 | Sheet and plate | Alloy 1100 is commercially pure Al, but has some Si and Fe which diminish reflectivity under anodized coating. Presence of Si can give coating a gray or brown tint. Alloy 5005 has some for moderate strengthening. |
| 3003 | Al-Mn alloy in sheet or plate | This commercial alloy has excellent formability and, though widely used for anodic finishing, has less reflectivity than 1100 or 5005 after anodizing because of Mn and lower Al purity. Since MnO is brown, thick anodized films on this alloy have a brownish tint. |
| 5052 | Al-Mg alloy in sheet or plate | Structural alloy containing Cr as well as Mg, widely used for welded parts. Presence of Cr gives thicker anodic coatings a yellowish tint. |
| 6061 2014 2024 7075 | Extrusion, sheet and plate | Heat-treatable, these alloys rank after 5052 in reflectivity because Al purity is lower. Cr in 6061 and 7075 gives thicker anodic coatings a yellowish tint. |
| Reprinted from Product Engineering | ||