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Salt Spray test for ASTM B-633 Type II, FE/AN 5 with Olive Drab Chromate and Top Coat Passivate

Would you expect a steel fitting coated per 'ASTM B633 TYPE II, FE/ZN 5 with Olive Drab Chromate and Top Coat Passivate' to pass a salt spray test to 168 hrs to white and 300 hrs to red corrosion? Additionally, is the above plating 'ASTM B633 TYPE II, FE/ZN 5 with Olive Drab Chromate and Top Coat Passivate' equivalent to British spec 'BS-1706: 1990, Class 2D'?

Arick Kaschalk
Machine Shop/ Distribution - Valley View, Ohio
2003

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Yes to the first question, Arick

To the second, is the Declaration of Independence equivalent to the Magna Carta? :-)
If the specs are not word-for-word identical, whether one is "equivalent" to the other is an indefinite and nebulous matter that can quickly lead to contract disputes. I'm not sure if BS 1706: 1990 Class 2D covers zinc on steel with olive drab chromate or not (maybe someone familiar with it can say)--but if the question came up then you need to get a copy of the specs because you have to plate to one or the other or both literally, not to equivalents :-)

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2003

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2003

BS 1706:1990 has been superseded by BS EN 12329, however you should have some codes specified with BS1706:1990 to tell you the minimum thickness to apply. Typically the spec quoted would be BS1706:1990 Fe/Zn5c 2D (if your customer requires 5 µm min local thickness), which means, Fe = Ferrous substrate, Zn = Zinc, 5 = 5 µm min thickness, c = chromate & 2D is the code for olive drab chromate. Other thickness codes are 8, 12 & 25 all for min local thickness in um, amongst the chromate codes are 1A Clear, 2C colour. The salt spray requirements for each thickness class and passivate type are comparable with ASTM B633. (remember 0.0001" is approx. 2.5 um) Hope this helps.

Regards,

Richard Guise
- Lowestoft, U.K.