Cross-group finish comparison
Aluminum Bright Dip vs Electropolishing
Aluminum Bright Dip (mechanical finishing) and Electropolishing (passivation & electropolishing) solve the same problem by different routes; electropolishing resists corrosion better.
Aluminum Bright Dip
Mechanical finishing · $$
Bright dipping is a chemical polishing pretreatment that levels microscopic peaks on aluminum to produce a reflective surface before anodizing.
Electropolishing
Passivation & electropolishing · $$$ · instant quote
Electropolishing is controlled anodic dissolution that brightens, deburrs, and smooths stainless steel and other qualified alloys.
When to choose which
Choose Bright dip
Bright dip is the pick when its strengths below matter more than Electropolishing's.
- Brightens many parts simultaneously by immersion
- Improves reflectance before clear anodize
- Reaches shapes that are difficult to mechanically buff
Choose Electropolishing
Choose Electropolishing when controlled electrochemical smoothing is appropriate.
- Removes about 5–25 µm per surface
- Reduces microscopic peaks and cleanability traps
- Deburrs very small edges without embedded abrasive
What the numbers say
- Electropolishing resists corrosion better.
- Bright dip is the lower-cost option ($$).
- Electropolishing is the thinner coating (removes 5–25 µm), so it disturbs tight fits less.
Scores side by side
Each score is 0–100 against every finish in this catalog. Corrosion is derived from salt-spray test duration and surface hardness from the finish layer's Vickers hardness where a measured figure exists; a finish that leaves the base metal's own surface is not rated for hardness. Cosmetic, lubricity and cost are FabDigit's engineering assessment. Scores and typical figures are screening data, not matched side-by-side tests or service-life rankings; ASTM B117 is a controlled salt-fog method, not a field-life prediction.
| Score | Bright dip | Electropolishing |
|---|---|---|
| Corrosion resistance | 2 Minimal | 45 Fair |
| Surface hardness / wear | — — | — — |
| Cosmetic quality | 88 Excellent | 82 Very good |
| Lubricity | 12 Minimal | 35 Fair |
| Cost | 32 $$ | 54 $$$ |
Key numbers
| Property | Bright dip | Electropolishing |
|---|---|---|
| Thickness | 0 µm | removes 5–25 µm |
| Electrical | Unchanged | Unchanged |
| Relative cost | Standard ($$) | Premium ($$$) |
| Added lead time | 3–6 working days | 3–6 working days |
| RoHS | Compliant | Compliant |
| Instant quote | On request | Yes |
Bold marks the side that is ahead on a row where more (or less, for cost and lead time) is better. Ranges are the typical specification window; the drawing call-out fixes the class.
Which materials take each finish
| Material family | Bright dip | Electropolishing |
|---|---|---|
| Aluminum | Yes | Limited |
| Stainless Steel | No | Yes |
| Cobalt-Chrome Alloy | — | With care |
| DMLS / SLM | — | With care |
| Nickel Alloy | — | With care |
| Brass | No | Limited |
| Copper Alloy | No | Limited |
| Steel | No | Limited |
| Titanium | No | Limited |
Specifications and drawing call-outs
Bright dip
No governing public specification — called out by name and thickness.
CHEMICALLY BRIGHT DIP ALUMINUM TO MATCH APPROVED LIMIT SAMPLE FD-BD-01, THEN CLEAR ANODIZE PER MIL-A-8625 TYPE II CLASS 1, 0.0003–0.0005 IN
Electropolishing
- ASTM B912 — Standard Specification for Passivation of Stainless Steels Using Electropolishing
ELECTROPOLISH STAINLESS STEEL PER ASTM B912; REMOVE 0.0002–0.0005 IN PER SURFACE; FINAL Ra 0.4 µm MAX; MASK THREADS
Bright dip vs Electropolishing — frequently asked
What is the difference between Bright dip and Electropolishing?
Aluminum Bright Dip (mechanical finishing) and Electropolishing (passivation & electropolishing) solve the same problem by different routes; electropolishing resists corrosion better. Bright dip is the lower-cost option ($$). Electropolishing is the thinner coating (removes 5–25 µm), so it disturbs tight fits less.
When should I use Bright dip instead of Electropolishing?
Conversely: choose Electropolishing when controlled electrochemical smoothing is appropriate.
Is Bright dip or Electropolishing cheaper?
Bright dip is the lower-cost finish ($$ against $$$ for Electropolishing) 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.