When should I specify silver plating over tin?

Silver plating is preferred when the terminal must carry higher currents, operate at higher temperatures (above 150°C), or withstand more mating cycles. Silver's conductivity (105% IACS) is significantly better than tin's (15% IACS). However, silver costs approximately 3-5× more than tin and can tarnish in sulfur-rich environments.

Can stamped parts be powder coated?

Yes. Powder coating is an excellent finish for stamped parts that require thick, durable corrosion protection — typically 60-120 μm coating thickness. It's commonly used for brackets, enclosures, and structural components. However, powder coating cannot be applied to electrical contact surfaces.

How does zinc plating compare to hot-dip galvanizing?

Zinc plating (electrogalvanizing) applies a thin (5-15 μm) layer of zinc and is suitable for indoor applications. Hot-dip galvanizing applies a thicker (50-150 μm) coating by immersing the part in molten zinc, providing significantly better corrosion resistance for outdoor use.

What is passivation and when is it needed?

Passivation is a chemical treatment that removes free iron from the surface of stainless steel parts and promotes the formation of a protective chromium oxide layer. It's recommended for stainless steel stamped parts used in corrosive environments, medical devices, or food processing equipment.

Metal Stamping Surface Finishing: Plating, Passivation, and Coating Options

Q: What is the most common plating for stamped electrical terminals?

Tin plating is the most common finish for electrical terminals and connectors. It provides good corrosion resistance, excellent solderability, and low cost. Typical thickness is 2-8 μm for electronic connectors and 8-15 μm for automotive/EV terminals.

Metal stamping surface finishing guide: compare plating, passivation, anodizing, and powder coating for stamped parts. Learn how surface treatment affects corrosion resistance, conductivity, and part durability.

Electroplating Options

Tin Plating

The most widely used finish for electrical terminals and connectors. Tin provides good corrosion resistance, excellent solderability, and is cost-effective. Available as bright tin or matte tin. Typical thickness: 2-15 μm.

Nickel Plating

Electroless or electrolytic nickel provides excellent wear resistance and corrosion protection. It serves as an undercoat for gold or silver plating, or as a standalone finish for parts operating at elevated temperatures. Typical thickness: 3-20 μm.

Silver Plating

Offers the highest electrical conductivity (105% IACS) of any common plating. Used for high-current terminals, switch contacts, and RF connectors. Requires anti-tarnish treatment. Typical thickness: 2-10 μm.

Zinc Plating

Low-cost corrosion protection for steel parts. Available with clear, yellow, blue, or black passivation. Salt spray resistance ranges from 24 hours (clear) to 120 hours (thick yellow). Typical thickness: 5-15 μm.

Plating Type	Conductivity	Corrosion Resistance	Relative Cost	Common Applications
Tin	Good	Good	$	Terminals, connectors
Nickel	Moderate	Excellent	$$	High-temp contacts, underplate
Silver	Excellent	Moderate	$$$	High-current, RF connectors
Zinc	N/A	Good	$	Structural brackets, hardware

Chemical Conversion Coatings

Passivation

For stainless steel parts: removes free iron and forms a protective chromium oxide layer. Required for medical, food-grade, and marine applications. Typically specified to ASTM A967.

Anodizing

For aluminum stamped parts: creates a hard, wear-resistant oxide layer. Available in clear, black, or colored finishes. Provides excellent corrosion protection and can serve as a paint primer.

Mechanical Finishing

Deburring

Removes sharp edges and burrs from stamping. Methods include vibratory finishing, tumbling, brushing, and manual deburring. Consistent deburring is critical for terminals that will be handled during assembly.

Vibratory Finishing

Used for bulk processing of small stamped parts. Can achieve edge rounding, surface smoothing, and light deburring. Media and compound selection depends on the material and desired finish.

Specifying Surface Finish

When specifying surface finish for stamped parts, include:

Material and grade
Plating or coating type and thickness
Surface roughness requirement (Ra in μm)
Salt spray test requirement (hours to white/red rust)
Any selective plating requirements (which surfaces should/shouldn’t be plated)
Plating adhesion test requirement

VOLCRIX offers complete surface finishing support for stamped parts, including in-house plating partnerships and full quality documentation for every batch.