Trivalent chromate with zinc color shall be indicated as "Ep-Fe/Zn5/CM2 (trivalent chromate)

April 21, 2022

 

Here.Numerous plating　One of the "one of theZinc trivalent chromate (zinc plated colored trivalent chromate)Here is a note about "The

 

Table of Contents
  1. Zinc colored trivalent chromate (Zinc plated colored trivalent chromate)

Zinc colored trivalent chromate (Zinc plated colored trivalent chromate)

Quickly, the indications for zinc colored trivalent chromate are as follows.

 

Zinc colored trivalent chromate:Ep-Fe/Zn5/CM2 (trivalent chromate)

 

The alphabetic symbols have the following meanings and are separated by a "/" (slash).

 

  • Ep-Fe: Symbol for electro-galvanization, a process of electroplating (Ep) on an iron base (Fe).
  • Zn5: Area specifying a minimum thickness of 5 μm for zinc plating
  • CM2: Chromate (CM) colored (2) is specified for the area

 

And,Meaning of (trivalent chromate) listed at the end　However, although JIS indicates hexavalent chromateSince trivalent materials are not specified in the JIS standard, it is necessary to separately state that trivalent materials should be used if indicated in the drawings.Therefore, in this article, it is described as Ep-Fe/Zn5/CM2 (trivalent chromate).　Therefore, it is acceptable to write Ep-Fe/Zn5/CM2, zinc trivalent chromate, on the drawing.

 

 

Supplement 1: About Electrogalvanization

The Zn5 part of Ep-Fe/Zn5 indicates the minimum thickness, and the following types are available.

 

Class 1: Min. plating thickness 2μ ⇒ Ep-Fe/Zn2 (Ep-Fe/Zn[1])
Class 2: Min. plating thickness 5μ ⇒ Ep-Fe/Zn5 (Ep-Fe/Zn[2])
Class 3: Min. plating thickness 8μ ⇒ Ep-Fe/Zn8 (Ep-Fe/Zn[3])
Class 4: Min. plating thickness 12μ ⇒ Ep-Fe/Zn12 (Ep-Fe/Zn[4])
Class 5: Min. plating thickness 20μ ⇒ Ep-Fe/Zn20 (Ep-Fe/Zn[5])
Class 6: Min. plating thickness 25μ ⇒ Ep-Fe/Zn25 (Ep-Fe/Zn[6])

 

The above thicknesses can also be expressed as a grade. （The class designations in parentheses ( ) indicate equivalent meanings, though,Generally, Ep-Fe/Zn5 etc.I think.

 

 

Supplement 2: Symbol Indication Method for Electroplating (Regarding the Color of Chromate)

The color of chromate is described in JIS H 0404.

 

this timeCM2 is colored chromate treatment　Other examples include CM1 bright chromate treatment and bk black chromate.

 

That's it.

 

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