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Black annealed phosphate coated wire / oil residue

Our company buys wire from China. The wire has been phosphate coated and drawn to 1.6 mm. The problem is that the wire has an oily residue. Is this problem due to the wire not being cleaned properly. Can someone please explain the process and perhaps the solution to this problem so that I can advise our supplier.

Dan Keen
Import - UK
2005

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It is probably oiled after phosphating because of justifiable fear that it will otherwise rust. Oiling is an important part of the corrosion fighting system. If you don't want it oiled, I think the vendor will comply . . . but then you may be dealing with flash rust issues or corrosion in transit.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2005

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I agree with Ted Mooney that the wire might have been oiled after phosphating to protect it from flash rusting and corrosion during transit. However, since the wire is drawn to 1.6 mm, it appears that the supplier might have used sodium stearate or similar proprietary formulations as they might assist in drawing operation.

T.S.N. Sankara Narayanan
- Chennai, Tamilnadu, India
(ed.note: The good doctor offers a fascinating blog, "Advancement in Science" )
2005