Cross-group finish comparison
Anodizing Type II vs Aluminum Bright Dip
Anodizing Type II (anodizing & conversion coatings) and Aluminum Bright Dip (mechanical finishing) solve the same problem by different routes; type II anodize resists corrosion better.
Anodizing Type II
Anodizing & conversion coatings · $$ · instant quote
Type II sulfuric anodizing converts aluminum into a porous aluminum-oxide coating that can be clear or dyed.
Aluminum Bright Dip
Mechanical finishing · $$
Bright dipping is a chemical polishing pretreatment that levels microscopic peaks on aluminum to produce a reflective surface before anodizing.
When to choose which
Choose Type II anodize
Choose Type II anodize when corrosion protection is required without chemical brightening.
- Provides a hard 200–400 HV oxide
- Supports clear and many dyed colors
- Sealed coatings meet a 336-hour ASTM B117 requirement under MIL-A-8625
Choose Bright dip
Bright dip is the pick when its strengths below matter more than Type II anodize's.
- Brightens many parts simultaneously by immersion
- Improves reflectance before clear anodize
- Reaches shapes that are difficult to mechanically buff
What the numbers say
- Type II anodize resists corrosion better.
- Type II anodize is the lower-cost option ($$).
- Bright dip is the thinner coating (0 µm), so it disturbs tight fits less.
- Type II anodize is insulating; Bright dip is unchanged.
Scores side by side
Each score is 0–100 against every finish in this catalog. Corrosion is derived from salt-spray test duration and surface hardness from the finish layer's Vickers hardness where a measured figure exists; a finish that leaves the base metal's own surface is not rated for hardness. Cosmetic, lubricity and cost are FabDigit's engineering assessment. Scores and typical figures are screening data, not matched side-by-side tests or service-life rankings; ASTM B117 is a controlled salt-fog method, not a field-life prediction.
| Score | Type II anodize | Bright dip |
|---|---|---|
| Corrosion resistance | 71 Very good | 2 Minimal |
| Surface hardness / wear | 54 Fair | — — |
| Cosmetic quality | 88 Excellent | 88 Excellent |
| Lubricity | 18 Low | 12 Minimal |
| Cost | 24 $$ | 32 $$ |
Key numbers
| Property | Type II anodize | Bright dip |
|---|---|---|
| Thickness | 5–25 µm | 0 µm |
| Surface hardness | 200–400 HV | — |
| Salt-spray test duration | 336 h | — |
| Max service temperature | 80 °C | — |
| Electrical | Insulating | Unchanged |
| Colours | clear, black, red, blue, gold, custom dye | — |
| Relative cost | Standard ($$) | Standard ($$) |
| Added lead time | 3–5 working days | 3–6 working days |
| RoHS | Compliant | Compliant |
| Instant quote | Yes | On request |
Bold marks the side that is ahead on a row where more (or less, for cost and lead time) is better. Ranges are the typical specification window; the drawing call-out fixes the class.
Which materials take each finish
| Material family | Type II anodize | Bright dip |
|---|---|---|
| Aluminum | Yes | Yes |
| DMLS / SLM | With care | — |
Specifications and drawing call-outs
Type II anodize
- MIL-A-8625 — Anodic Coatings for Aluminum and Aluminum Alloys
- AMS 2471 — Anodic Treatment of Aluminum Alloys, Sulfuric Acid Process, Undyed Coating
- AMS 2472 — Anodic Treatment of Aluminum Alloys, Sulfuric Acid Process, Dyed Coatings
- ISO 7599 — Anodizing of Aluminium and Its Alloys — Method for Specifying Decorative and Protective Anodic Oxidation Coatings on Aluminium
ANODIZE PER MIL-A-8625 TYPE II CLASS 2, BLACK, 0.0005 IN THICK; MASK ALL THREADS AND ELECTRICAL CONTACTS
Bright dip
No governing public specification — called out by name and thickness.
CHEMICALLY BRIGHT DIP ALUMINUM TO MATCH APPROVED LIMIT SAMPLE FD-BD-01, THEN CLEAR ANODIZE PER MIL-A-8625 TYPE II CLASS 1, 0.0003–0.0005 IN
Type II anodize vs Bright dip — frequently asked
What is the difference between Type II anodize and Bright dip?
Anodizing Type II (anodizing & conversion coatings) and Aluminum Bright Dip (mechanical finishing) solve the same problem by different routes; type II anodize resists corrosion better. Type II anodize is the lower-cost option ($$). Bright dip is the thinner coating (0 µm), so it disturbs tight fits less.
When should I use Type II anodize instead of Bright dip?
Choose Type II anodize when corrosion protection is required without chemical brightening.
Is Type II anodize or Bright dip cheaper?
Type II anodize is the lower-cost finish ($$ against $$ for Bright dip) among the finishes FabDigit quotes. Both are priced per part with a lot minimum; the exact figure appears on the instant quote once the part is uploaded.