Silver contact and what looks like a contact bar.

This was from an old fire control panel. I have about 40 of them. All the contact points are gold plated silver. Was wondering if that bar is also silver. It's non magnetic melted with map gas (barely) and is a silver color. Could this be silver as well? Also wondering what the pins might be. Could they have used nickle? They wouldn't be silver would they?

What does a drop of nitric do on them?

Relay legs are usually made from a brass tube with a wire soldered into the center with tin-led solder. The pin is fastened in the socket as a rivet.

I have never seen silver pins, only brass ones. I usually check for brass by bending the metal until it snaps and observe the color. If you cut it with pliers then the surface metal is smeared over the cut face and you can't see the inside composition.

And I agree with Topher, a drop of nitric and some salt will reveal if something is made of silver. Usually both contact sides in a relay are made of the same material, if one side is silver then the other side should also be silver. Alternatives to silver is a rather thin silver surface with brass backing and I've even seen silver plate.
If the contact points are gold plated then the receiving surface should also be gold plated.

Göran

Definitely not brass. It's a silver color and not a tube but solid. I won't have nitric until next week. It does have a lead soldered wire. If it is silver will the lead solder give me problems if I batch them up with the rest of the contact points or should I keep them separate.

And they also look gold plated.

Where do they look gold plated?

Here?-

If so, I don't think that is gold plating. And I would be willing to bet Göran is right about the composition of them.

But, when you get your nitric in, put a small drop on and see what it does. What colours it reports. And that can give a better idea.

He might be right that's it not silver but I'm almost 100% certain it's not brass. It definitely plated with something. I used a file and it's definitely silver colored underneath the plating. Would they use any other element? Maybe tungsten? The gold plated contact points are in direct contact with the bars that's what made me think the were silver as well. I'll use some nitric when I go back to work in two weeks. Happy holidays! Thanks for the input.

Oh you were talking about the pins. The pins are slightly magnetic and when filed no brass color shows. I used a hard disc magnet on them and it barely picked them up. Could they be nickle?

You guys seems to be correct. I checked the pins and they are brass with some heavy plating. The bars are about 80% silver and 20% copper. The points are the same but plated or overlayed with gold. Wonder what the pin plating was it seems to be magnetic.

If you are using a rare earth magnet, it can pick up the nickel substrate.
Try with a regular old magnet and see if it is still magnetic.

Yeah, I just used a magnet the scrap yard gave me and nothing. Would they be good to keep for any other uses or should I just throw them in the brass scrap. I only have about a pound of them.

If its copper plated with gold, you could just throw them in the stock pot and recover the gold whenever you process your waste stream.

Or you could save them for if you ever set up a sulfuric cell.
Or you could save them for if you ever set up a cyanide leech.

Beyond those 3 ideas, I have no clue

You forgot melting them down and selling them as "gold drops" on FeePay, but if you did that I wouldn't want to associate with you. :roll:

Dave

The contact points were gold plated silver and the pins are nickle substrate brass. Not bad I'll take the contact points and inquart some karat gold.