Letter 638

Nickel versus Tin Plated Wire

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I recently read the finishing page on the web, and I thought you might be able to help me find some information. I am interested in researching the pros and cons of Nickel versus Tin plated wire for use in the aerospace industry. I was curious to know if you could help direct me to possible sources of this type of information. I would appreciate any information that you have.

Thank you.

Amy A
Electrical Standards Engineer - The Boeing Company

Amy, why would you consider using nickel plated wire? I cannot think of any great advantage it would have over commercially available tin or silver plated wire (speaking as a pilot and a plater).

James Watts
- Navarre, Florida

Amy,
I'm not sure exactly where to look, however, a couple of possibilities might be mil specs, standards etc. and ASME literature. I think you might search with key word combinations of "wire, plating, tin, nickel, solderability, ductility".

Good luck

Paul D. Stransky, CEF
- Putnam, Connecticut

We restrict the use of anything tin plated for satellite use. Why? Because the stress of a tin plating can result in tin "whiskers." There was a GIDEP Alert about 3 years ago on same. You may wish to check with Boeing's GIDEP representative. Tin whiskers can cause electrical shorts and during a ground test triggered a >200 amp plasma short.

Dave Love
Aerojet

Amy,

Plating provides a couple of different thing for wire (Mil-W-22759) Tin provides a temperature rating of 150 C, Silver 200 C and Nickel 260 C. Nickel is used, obviously, when high temperature requirements are necessary. Tin is the most widely used in commercial aviation. Silver is secondary for higher temperature applications but must not be used in Severe Wind And Moisture Problem (SWAMP) areas like wheel wells and trailing edges of wing; silver plating when mixed with high pressure, current and glycol (wing deicer) can cause fire. Nickel is rather uncommon in commercial applications but is used.

Terry Foss
- Statesboro, Georgia