MIRALLOY® Copper-Tin-(Zinc-) Electrolytes

MIRALLOY® Copper-Tin-(Zinc-) Electrolytes

Barrel and rack plating electrolyte for functional applications

MIRALLOY® has been offering nickel-free plating for the connector, clothing and fashion jewellery industries for more than 30 years. You can benefit from our experience and the ongoing development of our product range. The trademark MIRALLOY® comes from the English words “mirror“ and “alloy“. It refers to the Bronze Age, when copper and tin were used to make mirrored alloys.

MIRALLOY® denotes electroplating processes for the deposition of alloy coatings of copper and tin or of copper, tin and zinc. Depending on the electrolyte used, white or yellow layers can be deposited. You can choose electrolytes for rack and barrel plating from the wide range of MIRALLOY® processes available.

Electrolyte characteristics

Electrolyte type


Metal content

8.5 g/l Cu 34 g/l Sn 0.75 g/l Zn

pH value

> 13

Operating temperature

60 (58 - 62) °C

Current density range

0.5 (0.3 - 1) A/dm²

Plating speed

0.12 μm/min at 0.5 A/dm²

Anode material

MMO (type PLATINODE® 167, graphite)

Electrical conductivity

>50 m*(Ω*mm²)-1

Coating characteristics



Alloy composition

55 wt. % Cu 30 wt. % Sn 15 wt. % Zn

Colour of deposit



550 HV

Max. coating thickness

5 μm


  • White layer, similar to silver
  • Diamagnetic
  • High reflectivity
  • Good wear and corrosion protection
  • Abrasion- and tarnish-resistant
  • Can be combined with precious metals
  • Good sliding properties
  • High hardness
  • Solderable and weldable
  • Very good metal distribution
  • Low porosity
  • Free from heavy metals like CR, Pb, Co, Th etc.
  • Low intermodulation
  • Platings are RoHS-compliant


  • High frequency connectors
  • Battery covers
  • Hydraulic parts
  • Contact pins
  • Cooling coils
  • Bearing shells
  • Conducting elements


  • Produktblatt-miralloy-copper-tin-zinc-en-screen-20190416.pdf

MIRALLOY® coatings are characterized by an excellent thickness distribution even in the case of parts with complex shapes. The coating hardnesses of MIRALLOY® layers are 400 HV 0.1 (MIRALLOY® yellow) and 550 HV 0.05 (MIRALLOY® white). The layers are abrasion-resistant. For this reason yellow MIRALLOY® layers are particularly suitable for coating bearing shells or pistons. Furthermore, the layers are diamagnetic. Therefore connectors for high-frequency technology provided with MIRALLOY® coatings reach very low intermodulation values in the mobile radio frequency range.

Intermodulation at 935/960 Mhz (GSM)
f1 = 935 MHz at 43 dBm (20 W)               ------->               fIM3 = 2 x f1 - f2 = 910 MHz
f2 = 960 MHz at 43 dBm (20 W)

Your contact person

Markus Legeler

Manager Sales International
T: +49 7171 607 204
F: +49 7171 607 316

Find a representative in your region


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