Electroplating

Alkaline Zinc Plating (ASTM B633)

Alkaline (cyanide-free) zinc plating is the choice when coverage has to be even everywhere — including recesses and complex geometry. Its superior thickness distribution and throwing power make it a workhorse for fasteners and intricate hardware, with low-hydrogen-embrittlement variants for high-strength steel. Gleco plates alkaline zinc to ASTM B633 with RoHS-compliant trivalent chromates at our AS9100D and ISO 9001:2015 certified, ITAR Registered Texas plants.

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AS9100D
ISO 9001:2015
ITAR Registered
Rowlett & McAllen, TX

📍 Available at: Rowlett, TX (Dallas–Fort Worth) only

Alkaline vs. Acid (Chloride) Zinc

Attribute	Alkaline Zinc
Thickness distribution / throwing power	Excellent (uniform on complex shapes)
Brightness	Good
Best for	Complex, recessed, and fastener geometries
Efficiency / speed	Moderate
Governing spec	ASTM B633

Racked steel parts finished in clear alkaline zinc — Racked steel parts finished in alkaline zinc with a clear trivalent chromate. Alkaline zinc throws evenly into recesses and complex geometry.

See also our zinc plating overview and full ASTM B633 spec table, chloride (acid) zinc, and zinc-nickel for higher corrosion performance.

Alkaline Zinc FAQ

What is the advantage of alkaline zinc over acid zinc?

Alkaline (cyanide-free) zinc gives far more uniform thickness distribution and throwing power, so recessed and complex parts get consistent coverage. That uniformity is why it is preferred for many fastener and hardware applications, and low-hydrogen-embrittlement variants are available for high-strength steel.

Is alkaline zinc good for complex or recessed parts?

Yes. Its excellent throwing power (commonly better than 2:1 thickness distribution) makes it the better choice for parts with recesses, blind features, and complex geometry where acid zinc would build unevenly.

What chromates and colors are available?

Clear, yellow/iridescent, and black finishes, in RoHS-compliant trivalent chemistry (ASTM B633 Types III, V, and VI), with hexavalent only where a legacy specification requires it.

Is alkaline zinc RoHS compliant?

Yes, with trivalent passivates. We use hexavalent chromate only when the controlling drawing demands it.

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Precision metal finishing since 1979. Plating, anodizing, coatings and passivation from two Texas plants.

AS9100D
ISO 9001:2015
ITAR Registered
DFARS Compliant
RoHS

Services

Company

Locations

Gleco Rowlett
2220 Grisham Drive
Rowlett, TX 75088
972-475-4300

Gleco McAllen
3800 W. Ursula Ave
McAllen, TX 78503
956-800-4069

info@glecoplating.com