ASTM-B940 Standard Practice for Testing Non-Chromate Coatings on Zinc and Cadmium Surfaces

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Standard Practice for Testing Non-Chromate Coatings on Zinc and Cadmium Surfaces




1.1 This practice covers a procedure for evaluating the protective value of chemical and electrochemical conversion coatings produced by non-chromate (chromate being defined as a compound that has chromium in the plus six oxidation state, and as such, chromium compounds in other oxidation states, such as plus three, shall not be excluded) treatments of zinc and cadmium surfaces.

1.2 The protective value of a non-chromate coating is usually determined by salt-spray test and by determining whether or not the coating possesses adequate abrasion resistance when applied for that purpose.

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Significance and Use

4.1 This practice is applicable to non-chromate coatings that are colorless, colored, electrochemically applied or non-electrochemically applied. The zinc or cadmium, or both, may be electrodeposited, mechanically deposited, hot-dipped, rolled, or in the form of castings.

4.2 Because of variables inherent in the salt-spray test which may differ from one test cabinet to another, interpretation of test results for compliance with expected performance should be specified by the purchaser.

4.3 Properties such as thickness, color, luster, and ability to provide good paint adhesion are not covered in this practice, nor are the chemical composition and the method of application of these finishes.


non-chromate coatings;; ICS Number Code 25.220.99 (Other treatments and coatings)

To find similar documents by ASTM Volume:

02.05 (Metallic and Inorganic Coatings; Metal Powders and Metal Powder Products)

To find similar documents by classification:

25.220.99 (Other treatments and coatings)

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Document Number


Revision Level

2005 R14 EDITION



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Publication Date

Dec. 1, 2014

Document Type


Page Count

2 pages

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