Silvery metal.
Cannot solder with resin flux.
Can solder with plumbers flux (zinc chloride).
Non-magnetic.

 

Inconel?

Mabye you need some Indium solder…

 

I doubt it is anything that fancy. It is essentially just a weight in a model train loco. It is used to carry power from the track to the motor and I am modifying it to add a DCC decoder so I need to modify this connection and so to connect a wire to this piece of metal. It is N gauge so there isn't much space to add e.g. a screw connection.

As I have discovered that I can solder to it with plumbers solder my problem is solved but I am curious as to what it is.

 

Is it hard or soft? Does it seem as dense as lead or less so?

 

It is lighter and harder than lead but probably softer than steel. It has a black coating which seems to be conductive. I suspect it is diecast if that helps.

 

Model railroad trains that I've seen, typically older ones, used an alloy that I've heard that was called "base metal alloy". In doing a web search on base metal it is defined as non-ferrous metals such as copper, lead, nickel and zinc. The alloys on those trains were probably heavy on the nickel, lead and zinc with some amount of magnesium or aluminum as well. It was often used in diecast parts.

That's probably what you have. I've never tried soldering the "base metal" alloys from model trains, but every epoxy that I've tried did not hold well.

 

Probably a zinc-based alloy known as “monkey metal” - a fairly random low-quality alloy that is probably made from the sweepings-up from the workshop.

 

It is lighter and harder than lead but probably softer than steel. It has a black coating which seems to be conductive. I suspect it is diecast if that helps.

If it's a dedicate weight, it might be Babbitt (sometimes erroneously called "white metal"). The black coating might indicate protection against handling lead which is a concern of course.I would expect Babbitt to be easy to solder, tough.

 

Sounds like Pot Metal.

 

Yeah, so it is probably some random mixture of metals to keep the costs down. I didn't know such things existed so I've learned something new - thanks.
It would have been a problem connecting wires to it, but I do have a method of soldering to it so all is well.