DiFruscia Industries zinc plates iron and steel parts to ASTM B633, under DFI’s AS9100D quality system. Zinc plating is not a Nadcap special process.

What zinc plating does

Zinc protects steel sacrificially: the zinc corrodes first, so the steel underneath stays protected even where the coating is scratched. A chromate or passivate applied after plating extends corrosion resistance and sets the color. See Zinc.

How an ASTM B633 callout works

Part of the callout	What it sets
Service condition (SC 1–4)	The minimum zinc thickness
Type	The treatment after plating, including non-hexavalent options

What to expect

Sacrificial protection for iron and steel.
Clear or colored, depending on the treatment after plating.
Barrel plated. Small parts tumble in a rotating, perforated barrel in the plating bath, for an even, economical finish on high volumes of fasteners, pins, contacts and other small components.

How to call it out on the drawing

Give the service condition and type, for example ASTM B633, SC 2, Type II.
Choose a RoHS-compliant type where hexavalent chromium is not allowed.
High-strength steels may need hydrogen embrittlement relief baking after plating. Put the part’s hardness on the PO.
Barrel plating suits small, robust parts. For delicate, large or cosmetic-critical parts, ask DFI about a different approach.

Where it’s used

Fasteners, industrial hardware, automotive parts, brackets and stampings.

Get a quote or a data sheet

Send the drawing and the spec callout to rfq@difruscia.com, or use Request a Quote. DFI’s technical data sheet for this process is available on request from Technical Specifications. Questions: 401.943.9900 or support@difruscia.com.

Values shown are typical results for reference only and are not specification limits. Results vary with alloy, part geometry, thickness and process parameters. Contact DFI to confirm the requirements for your application.

ASTM B633 Zinc Plating on Iron and Steel