Surface Treatment Comparison

Comparison Table

Treatment	Best On	Protection	Appearance	Relative Cost
Type II Anodizing	Aluminum	Good corrosion + wear	Dyed colors, matte	$
Type III (Hard) Anodizing	Aluminum	Excellent wear	Dark gray/black	$$
Zinc / Nickel Plating	Steel	Good corrosion	Bright	$
Passivation	Stainless steel	Removes free iron, boosts corrosion	Unchanged	$
Powder Coating	Steel, aluminum	Excellent	Durable colors	$$
Bead Blasting	All metals	None (cosmetic)	Smooth satin matte	$
Electropolishing	Stainless	Adds corrosion resistance	Mirror bright	$$$

Choosing a Finish

• Aluminum parts: Type II anodizing for color + corrosion; Type III hard coat for moving/wear surfaces
• Carbon steel: zinc plating for interior parts, powder coat for exterior or cosmetic parts
• Stainless steel: passivation as standard; electropolish when a bright, clean surface matters (food, medical, semiconductor)
• Aesthetic: bead blasting before anodizing gives a uniform matte look; paints offer the widest color range
• Conductive surfaces: leave machined or mask specific areas before conversion coating

Tell Hold-Tech the operating environment and appearance target — we will recommend a finish that balances cost and performance.