Is this Aluminum wire?

[Robert Foster]

Is the upper conductor in this pic aluminum ? The house was built in 1954.

Thank you.

[Jim Port]

Based on the fabric covered insulation I would say it is tinned copper.

[John Arnold]

If you have pics from a different angle you may be able to see copper on the cut end.
Looks like tin coated copper to me, too.

[Robert Foster]

Thank you for the quick replies....unfortunately, the end of the conductor was inserted so far into the fuse holder that I couldn't see the end and take that picture...

[Jack Feldmann]

I'm going with tinned copper. You can sometimes get a better look at the neutrals.

[Robert Meier]

It's not aluminum. :)

[John Arnold]

...You can sometimes get a better look at the neutrals.

Excellent point.

[Stephen G]

They appear to be the same size, aluminum would be a larger wire for same service...

but why tin only one wire...did some older wires come pre-tinned

[Jerry Peck]

They appear to be the same size, aluminum would be a larger wire for same service...

but why tin only one wire...did some older wires come pre-tinned

Copper reacts with the compounds in the rubber, so the entire length of the conductors in the rubber insulation are tinned.

The conductor which is not tinned is likely a newer conductor with thermoplastic insulation, no tinning required.

When you see tinned copper (and thus rubber insulation) it is time to re-wire because the rubber dries out and becomes brittle and cracks, effectively cracking micro-cracks along the wire, and each of those cracks is a leakage point for the voltage and current on that wire to try to find any other path back to the source.