I'm looking for a plating spec.

[QAFitz]

A customer has called out a cadmium plating spec (A165 Type TS and has added that the parts shall be subsequently bi-chromatized in accordance with B201.
What is "bi-chromatized" ? I've seen dichromate conversion coating but not "bi-chromatized".
Thanks in advance for your time.

 

[CoryPad]

ASTM B 201 provides information on testing chromate coatings, but not how to coat items with chromate.

ASTM A 165 was withdrawn in 1988 and replaced with ASTM B 766. It contains information regarding chromate treatments.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[israelkk]

QQ-P-416 at

http://assist.daps.dla.mil/eAccess/...689EBD&s_key=79359CD6C4C995D87552A047544F4D2A

 

[kenvlach]

Bichromate and dichromate are synonyms; the latter is preferred.
chromatized is a malapropism for chromated.

The obsolete ASTM A165 'T.S.' is a 0.00015" (3.8 microns) minimum thickness cadmium plating. The closest equivalent in ASTM B766 is 'Class 5,' 5 microns minimum thickness.

ASTM B201 is not a chromating specification. It is a testing procedure for chromated cadmium; the chromating is performed if and as specified by purchaser, as part of ASTM B766.
In ASTM B766, Type II is colored chromate (e.g., yellow), Type III is colorless chromate.

QQ-P-416F PLATING, CADMIUM (ELECTRODEPOSITED) (S/S BY SAE-AMS-QQ-P-416) is available below (israelkk's link gave me an error message):

http://assist.daps.dla.mil/quicksearch/basic_profile.cfm?ident_number=51006

 

[TVP]

kenvlach said malapropism.