Is this aluminum wiring?

Hello all trying to determine if this is aluminum or the coated copper. 2nd wire down from top. Home was built in 1948 most of the panel is copper.

Following I’m curious as well.

Tinned Copper

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Jim’s got it.

Yeah, Jim’s always had a knack of tasting things to know what they are. :wink::smiley:

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As previously mentioned tinned copper. Tell tale sign is the covering on the wire. The old material covers will be tin copper. Aluminum will have vinyl covering.


Awesome thank you!! That was gonna be my next question. Is there a way to confirm.

The rubberized insulation under the clothed jacket likes to get brittle after x amount of years… just saying.

Saying ALU wire is always covered in vinyl isn’t true. A more accurate way is looking at the conductor size.

What other materials have you experienced, Pierre?

At least in Canada you can see cloth covered.

A more accurate way of deciphering the covering of aluminum wire is by its size?

I don’t get that. Can you explain further?

Aluminum wire was not made in size 14 American Wire Gauge. 12 Gauge was used for 15 ampere circuits and 10 gauge was used for 20 Ampere circuits. So a 12 gauge wire on a 15 ampere breaker is at least suggestive of Aluminum wire.

Tom Horne

“Aluminum will have vinyl covering.” :face_with_monocle::writing_hand:
Not always the case. One should never use that narrative nor think that way.
History of Old Electrical Wiring

Observation. Branch circuits. (1) Old cloth/fabric NMC insulated cable. Conductor can/maybe Aluminum or Tinned copper. Lower heat rating due to cloth/fabric insulator.
Recommend: A licensed electrical contractor review 'all branch circuits and panel terminations."
A branch circuit conductor update may be in order for the NMC cloth/fabric branch circuit.
Act upon any recommendations provided.

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I get that, Pierre.

I thought we were talking about the wire covering.

Really? Based on what? I agree that wire size is an accurate indicator. For a younger inspector this may be a harder determination, especially viewing in a panel. Have you ever seen single stand aluminum wire in a cloth sheathing? The reverse of that, have you seen tinned copper with vinyl?

It must be a simple miscommunication between Pierre and me.

Good inspecting!..:smile:

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you will find aluminum wire used during the vietnam war years