ISO 10074
Anodizing of Aluminium and Its Alloys — Specification for Hard Anodic Oxidation Coatings on Aluminium and Its Alloys
Specifies requirements and test methods for hard anodic oxidation coatings on wrought and cast aluminum alloys, excluding plasma-electrolytic processes.
What ISO 10074 specifies
ISO 10074 specifies hard anodic oxidation and classifies the substrate into five alloy groupings because alloy chemistry strongly affects attainable coating density, hardness, wear, and appearance. It does not use the AA5–AA25 decorative thickness classes. Typical purchaser-selected thicknesses span about 25–150 µm, with 50–80 µm normal for hard anodizing, but the order must state the required value. The standard covers appearance, thickness, surface density, abrasion, Vickers microhardness, corrosion, breakdown voltage, and process qualification. Buyers should state alloy class, significant surfaces, thickness or final dimensions, sealing, and required optional tests.
ISO 10074 types and classes
Every designation the document defines, with the thickness it requires and the tests it imposes.
| Designation | Meaning | Coating weight | Requirement / test |
|---|---|---|---|
Class 1 | All wrought alloys except those assigned to Class 2. | At 50 ± 5 µm, minimum surface density 1100 mg/dm². | Thickness, surface density, wear, and hardness. |
Class 2(a) | 2000-series alloys and other alloys containing more than 5% copper. | At 50 ± 5 µm, minimum surface density 950 mg/dm². | Thickness, surface density, wear, and hardness. |
Class 2(b) | 5000-series alloys with at least 2% magnesium and 7000-series alloys. | At 50 ± 5 µm, minimum surface density 950 mg/dm². | Thickness, surface density, wear, and hardness. |
Class 3(a) | Casting alloys with less than 2% copper and/or 8% silicon. | At 50 ± 5 µm, minimum surface density 950 mg/dm². | Thickness, surface density, wear, and hardness. |
Class 3(b) | Other casting alloys. | By agreement. | Requirements agreed between purchaser and anodizer. |
Tests and the drawing call-out
Tests the document imposes
- Thickness by ISO 2360 or ISO 1463
- Surface density by ISO 2106
- Abrasive-wheel, abrasive-jet, or Taber abrasion
- Vickers microhardness
- Corrosion resistance
- Breakdown voltage when specified
How to cite it
Drawing call-out
HARD ANODIZE PER ISO 10074, ALLOY CLASS <1|2(a)|2(b)|3(a)|3(b)>, <THICKNESS>, <SEAL>, <TESTS>Angle brackets mark the choices the drawing must make; every finish page shows a completed example.
Finishes specified to ISO 10074
ISO 10074 — frequently asked
Are ISO 10074 classes thickness classes?
No. Classes 1, 2(a), 2(b), 3(a), and 3(b) classify aluminum alloy groups. Thickness must be stated separately.
What hard-anodize thickness should a buyer specify?
Typical values are 25–150 µm, with 50–80 µm common. Fit, alloy, wear, and the ability to coat recesses should determine the drawing value.
Does ISO 10074 cover plasma electrolytic oxidation?
No. It explicitly excludes plasma, micro-arc, spark, and related plasma-electrolytic oxidation processes.
ISO 10074 is copyrighted by International Organization for Standardization. This page explains the document so a drawing can be read; it does not reproduce the standard. Purchase the current edition from the publisher. Official source ↗