📍 Available at: Rowlett, TX (Dallas–Fort Worth) & McAllen, TX (Rio Grande Valley)

Zinc Plating Specifications (ASTM B633)

Governing spec	ASTM B633 (current revision)
Service condition & thickness	SC 1 (mild) — Fe/Zn 5, 5 µm (0.0002 in); SC 2 (moderate) — Fe/Zn 8, 8 µm (0.0003 in); SC 3 (severe) — Fe/Zn 12, 12 µm (0.0005 in); SC 4 (very severe) — Fe/Zn 25, 25 µm (0.0010 in)
Finish types	Type I as-plated; Type II colored (iridescent) chromate; Type III colorless chromate; Type IV phosphate (paint base); Type V colorless trivalent passivate; Type VI colored trivalent passivate
Salt spray (ASTM B117)	Type II ≥ 96 h to white corrosion; Type III ≥ 12 h to white corrosion (hours to red rust scale with zinc thickness)
Chromate colors	Clear, yellow/iridescent, black
RoHS	Types III, V, VI are the RoHS-compatible (trivalent) routes
Typical callout	“Zinc plate per ASTM B633, Fe/Zn 8, Type II, SC 2”
Typical uses	Fasteners, brackets, stampings, hydraulic fittings, general industrial hardware

Zinc-plated steel tubing finished with a yellow iridescent chromate — Zinc-plated steel tube finished with a yellow iridescent chromate, plated on our Rowlett zinc line. Colour comes from the chromate conversion coating, not the zinc itself.

Which Zinc Process Is Right for Your Part?

Rack & Barrel Capacity

We run both rack and barrel zinc lines — barrel for high-volume small parts, rack for larger or more delicate work — with parts handled up to 120 in. x 36 in. x 72 in. on our zinc line. Bath chemistry is analyzed and controlled daily by our in-house chemists, and every operator is certified through Gleco University.

FAQ

Zinc Plating FAQ

What salt spray life does zinc plating achieve?

It depends on thickness and chromate. Per ASTM B633, a colored (Type II) chromate must reach 96 hours to white corrosion and a colorless (Type III) chromate 12 hours; red-rust life then scales with zinc thickness (SC1–SC4). When you need substantially more corrosion life, zinc-nickel is the step up.

What is the difference between clear and yellow zinc chromate?

Clear (colorless) chromate is a brighter, more cosmetic finish with lower corrosion protection; yellow/iridescent chromate provides higher salt-spray performance. We offer clear, yellow, and black finishes in RoHS-compliant trivalent chemistry, with hexavalent only where a legacy specification requires it.

Rack or barrel zinc plating — which do I need?

Barrel plating is best for high volumes of small parts like fasteners and stampings; rack plating suits larger, heavier, or more delicate parts that need controlled contact and consistent thickness. We run both at each plant.

Is your zinc plating RoHS compliant?

Yes. Our trivalent passivates (ASTM B633 Types III, V, and VI) are RoHS-compatible. We use hexavalent chromates only when a controlling drawing or specification calls for them.

Do you bake for hydrogen embrittlement relief?

Yes. Post-plate embrittlement relief baking is performed per the governing specification for high-strength steels, with bake start time and duration documented in the job traveler.

Get a Zinc Plating Quote

Send your drawing, service condition, and chromate type and we will confirm the spec and quote it. Request a quote →

Zinc Plating Services (ASTM B633)

Zinc Plating Specifications (ASTM B633)

Which Zinc Process Is Right for Your Part?

Rack & Barrel Capacity

Zinc Plating FAQ

Get a Zinc Plating Quote

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