Silver Electroplating

Silver electroplating deposits a thin, conductive silver layer on metal parts for low contact resistance, solderability, and corrosion protection in controlled environments.

Overview

Silver electroplating applies an electrolytic silver deposit onto a conductive substrate (or onto a conductive underplate) to improve electrical performance, solderability, and reflectivity. It’s common on copper and copper alloys, steel with an underplate, and electrical connectors where low contact resistance matters.

Choose silver plating for parts that carry current, see sliding/plug-in contacts, or need reliable solder wetting. Typical thickness is a few microns up to ~25 µm depending on wear and life requirements; thicker deposits cost more and can affect fit.

Tradeoffs: silver tarnishes in sulfur-containing environments, which can increase contact resistance if not controlled; anti-tarnish topcoats help but can affect solderability. Plating adds thickness non-uniformly (edges build up), requires good masking for critical surfaces, and needs a compatible underplate on some substrates to prevent diffusion and adhesion issues.

Common Materials

  • Copper
  • Brass
  • Phosphor bronze
  • Beryllium copper
  • Steel
  • Nickel silver

Tolerances

±0.0002" to ±0.001" (thickness-dependent)

Applications

  • Electrical connectors and terminals
  • Relay and switch contacts
  • RF/EMI shielding components
  • Bus bars and power distribution hardware
  • Solderable pads and terminations
  • High-reflectivity optical reflectors

When to Choose Silver Electroplating

Select silver electroplating when electrical contact resistance, current carrying capability, or solderability drives performance and a metallic coating is acceptable. It fits low to high volumes, especially for connectors and contact hardware where thickness can be specified and controlled. Plan for masking and post-plate handling to manage tarnish and protect functional surfaces.

vs Anodizing

Choose silver electroplating when you need a highly conductive surface or solderability; anodizing produces an insulating oxide and won’t meet low-resistance contact requirements. Silver plating also works on many non-aluminum substrates where anodizing is not applicable.

vs Powder Coating

Choose silver electroplating when a thin metallic, electrically conductive finish is required; powder coat is thicker, nonconductive, and can interfere with tight fits and contact performance. Silver plating is better for mating interfaces and solderable areas that must remain metallic.

vs E-Coating

Choose silver electroplating for functional electrical surfaces; e-coat is primarily a corrosion/paint system and is typically insulating. Silver plating provides controlled metallic thickness and low contact resistance where electrical performance is the priority.

vs Nickel Electroplating

Choose silver electroplating when contact resistance and solderability are more critical than hardness and barrier performance. Nickel is harder and more corrosion-resistant in many environments, but it has higher contact resistance and can be difficult for soldering without activation.

vs Gold Electroplating

Choose silver electroplating when you need low resistance and good solderability at lower cost and can manage tarnish risk. Gold is more stable in corrosive/sulfur environments and for very low-level signals, but typically costs more for the same coverage.

Design Considerations

  • Specify plating thickness and tolerance zone on the drawing, and identify any surfaces that are thickness-critical for fit
  • Call out masking requirements explicitly (no-plate areas, contact pads, threads) and provide clear boundaries to avoid rework
  • Define required underplate(s) and substrate condition (e.g., nickel underplate on steel) to prevent diffusion/adhesion issues
  • Avoid sharp edges and burrs where plating will build up; break edges to reduce nodules and thickness variability
  • State tarnish-control expectations (anti-tarnish, packaging, storage life) and whether solderability must be preserved
  • Provide contact/wear requirements (mating cycles, current, sliding) so the shop can recommend an appropriate silver thickness and hardness