Zinc-iron alloy plating brightener system for alkaline baths

METASU AZ is an alkaline zinc-iron plating bath for general parts. The zinc-iron alloy plated film contains 0.3-0.6% of iron with high corrosion resistance.

  • High corrosion resistance can be obtained as compared with conventional zinc plating.
  • Similar to zinc plating, blackening or coloring with trivalent chromium passivation is possible.
  • A uniform alloy composition can be obtained over a broad range of electric current densities.
  • Superior throwing power and ductility for secondary process.

Product Specifications


Attributes Colorless transparent liquid (AZ-CONC)
Brown liquid (AZ-F210A)
Colorless transparent liquid (AZ-F3A)
Light yellow-yellowish brown liquid (AZ-GM)
Slightly murky-transparent liquid (AZ-GH)

The product color tone does not affect performance.


Usage conditions (standard)

Item Usage range
Composition Rack process Barrel process
Zinc metal 14 – 16 g/L 14 – 18 g/L
Caustic soda 110 – 130 g/L 110 – 140 g/L
Iron *1 0.25 – 0.4 g/L 0.25 – 0.45 g/L
Complexing agent *2 110 – 130 ml/L 80 – 150 ml/L
Condition Bath temperature 20 – 28°C
Cathode electric current density 1 – 4 A/dm2 0.4 – 1 A/dm2
Anode plate Mild steel plate
Oscillation Cathode locker 1-3m/min

Continuous filtration

(Installation of 2 systems is recommended, with one system to handle the main bath circulation and the other system for the zinc dissolution bath circulation)

*1,*2 Use METASU AZ-F210A (iron) and METASU AZ-F3A (complexing agent) for bath makeup.


Concentration and replenishment of brightener (standard)

Chemicals Rack process Barrel process
Standard bath makeup concentration Replenishment amount (L/KAH) Standard bath makeup concentration Replenishment amount (L/KAH)
METASU AZ-GM 10 ml/L 0.2 – 0.4 5 ml/L 0.1 – 0.3
METASU AZ-GH 10 ml/L 0.01 – 0.03 10 ml/L 0.01 – 0.05


Replenishment of the brightener varies depending on the current density and drag-out amount in the line.

For consistent plating performance, automatic replenishment is recommended since the brightener needs to be added in small quantities at short intervals.


Inquiry about the product

Feel free to contact us if you have any questions or matters to discuss.