Summary for silver vs tin plate Discussion
Silver plate vs tin plate on copper bus bars is discussed mainly in terms of contact performance, arcing, and cost. Gerrard Regier asked whether silver flash on copper offers an advantage over tin plate for telecommunications bus bars used around 20–60 volts and repeatedly plugged in and out, and whether a nickel barrier is needed under tin. Tom Pullizzi asked whether the issue was busbar connections or switchgear. Yashawant Deval said a nickel undercoat is required to prevent migration, silver is not known for arc resistance, tin oxide does resist arcing, and tin is acceptable if contact pressure is high; for light contact pressure, silver is preferred. Michael Brewington added that silver has the highest electrical and thermal conductivity of any metal. A later thread on tin plating contacts noted that if the plating is high quality, the surface material matters less, but wear-through and current-carrying capacity still matter, as Ted Mooney explained.
Q. We have a customer in the Telecommunications Industry. We have been plating copper bus bars in Silver Flash. They want to change to Tin Plate. What is the advantage of Silver on Copper over Tin on Copper or visa versa. They are working in the 20-60 volt range. They are plugging in and out. Does Silver Plate reduce Arcing? Is a Nickel barrier plate required between copper and tin? If so, the process is longer and no real cost saving results. We do not know how to advise our customer.
Can you help?
With thanks…
Gerrard Regier
– London, Ontario, Canada
Are you arcing in the connections of busbar, or is the application for switch gear?
Tom Pullizzi
Falls Township, Pennsylvania
A. A nickel undercoat will be required to prevent migration. Silver is not known to posses arc resisting property. Tin oxide does resist arc. If contact pressure is high, Tin plating should be quite O.K. For light contact pressure the choice has to be silver.
Yashawant Deval
– Pune, Maharashtra, India
Silver has the highest electrical and thermal conductivity of any metal.
Michael Brewington
– Salisbury, Maryland, USA
Q. I am also doing tin plating on copper contact.
Some platers suggest do it on brass, some others steel to reduce cost. I am worried about performance.
Can someone help me?
S.Goal
auto agency – Chennai,Tamil Nadu, India
April 2, 2010
A. Hi, S. If the plating is high quality, then the surface of the contact is tin; so if you are only concerned about surface characteristics, you can go with steel or whatever is cheapest.
However, this probably isn’t the usual case. Usually you have to worry about what happens if the plating wears thin if the contact is involved in a wear situation. And you may also have to be concerned with the current carrying capacity of the contact. Copper carries about 10x the current that steel does.
Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
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Need project assistance? $100/hr.
July 7, 2010
Adhesion Testing of Tin & Silver Plating on Bus Bars
Q. I would like to know the adhesion validation methods of tin plating / silver plating on copper busbars.
happy ratnan
plating shop – kuwait
March 28, 2016
A. Hi Happy. Usually the purchaser will tell you what spec you must plate in accordance with, and the spec will include the required compliance tests. The best adhesion tests often involve baking because this places stress on the plating … but this may be inapplicable in your case due to causing annealing of the bars. Tape tests are relatively easy to conduct, but are really designed more for painted coatings than plated coatings, and may be too easy to pass. There are chisel tests and other adhesion tests, but often the easiest to conduct, while still being a tough test on the adhesion is a bend test, where a sample must be bent 90° (or whatever) around a mandrel of a specified diameter and it is required that the plating not rip or spall.
If your customer has not given you plating specifications to meet, I would urge the two of you to get together and agree exactly what plating you are supposed to be doing. Perhaps ASTM B545 for tin plating and ASTM B700 for silver plating could be starting points for the discussion? Good luck.
Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
March 2016
A. Assuming that you want a non-destructive test, and baking is impractical, then a tape test is probably your best alternative.
Lyle Kirman
consultant – Cleveland Heights, Ohio
March 30, 2016
A. Good day Happy.
Why not try in an inconspicuous location to scribe the deposit to the base metal and perform a tape test, and try and “lift” the deposit from the base metal with a razor/exacto knife
⇦ on
or
Amazon [affil link] to determine adhesion?
Regards,
Eric Bogner, Lab. Tech
Aerotek Mfg. Ltd. – Whitby, Ontario, Canada
March 31, 2016