something interesting on silver electrical contacts

[nh6886]

Here are some of the contacts from 480v 3ph breakers with analysis. You can tell the tungsten ones visually by the waffle pattern on the back. It takes a long (by comparison) time to get the silver into solution from the the silver/tungsten contacts the upside is the solution is very clean. Read the many cadmium warnings on the forum before making a mess or worse breathing the fumes from melting the solder.
All the Best,
John

 

[CBentre]

Here's a few more silver items to throw up here for this thread, anyone have any experience with either? The second picture is from a automotive wiring harness and the first is from some RF equipment.

 

[Smack]

The second pic is brass with tin over it unless your test proved otherwise. The first pic looks like silver over brass, the color looks right on that one.

 

[etack]

What I have found to be true in contact points is that are from repairable units will have Ag alloy points and disposable units will have AgW points. lots of motor starts and relays are repairable whereas most breakers are not. This is not to be taken as a rule but as a guide. if you buy whole units to scrap this will help in knowing the cost of them. I personally buy them all as the contacts run 40%.It helps to know what the contacts weigh when you look at them. This is the time you buy points off ebay to just get a mix to know the different weights and sizes. I have small sample that i use to show people and to use to gauge what the return will be.

Eric