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Why plugs with galvanized or copper-plated steel pins instead of solid brass or CU? #18583
12/11/02 03:33 PM
12/11/02 03:33 PM
S
SvenNYC  Offline OP
Member
Joined: Aug 2002
Posts: 1,691
New York City
I see these for sale in hardware stores.

Most of them are Nema 1-15 caps, though (made either by Eagle Electric or Gem Electric).

Why make the pins out of steel instead of copper or brass?

Usually the pins wind up rusting after a few years in service, particularly when it's on something that gets constantly plugged and unplugged (and the zinc or copper plating rubs off the steel blade).

I've run across a number of such rusted attachment plugs on old lamps and other appliances

Normally I avoid them and choose copper bladed caps unless I have no choice, but it always intrigued me.

Also steel isn't that good a conductor, and don't you have some sort of reaction when you connect things like zinc/steel and copper, or is that only with aluminium?

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Re: Why plugs with galvanized or copper-plated steel pins instead of solid brass or CU? #18584
12/11/02 03:53 PM
12/11/02 03:53 PM
HotLine1  Offline

Member
Joined: Apr 2002
Posts: 6,919
Brick, NJ USA
Hey Swen:
My best guess, and IMHO:
Copper prongs on plugs would be to "soft", and would be an additional cost factor in mfg. Brass was/is used, also brass plating, and nickle plating on whatever base metal the mfg uses.

Im'm not a metalurgist, but I don't think there is a problem with any of the dissimilar metals you mentioned.

Also, you stated that you have seen "rusted" attachment plugs, I can't recall ever coming across any. I'm not doubting your comment, but are the ones you found a "factory" plug, or an aftermarket plug?; and are they from the USA??
John


John
Re: Why plugs with galvanized or copper-plated steel pins instead of solid brass or CU? #18585
12/11/02 04:18 PM
12/11/02 04:18 PM
S
SvenNYC  Offline OP
Member
Joined: Aug 2002
Posts: 1,691
New York City
I was referring normally to replacement (aftermarket) caps.

Most factory molded plugs are made of what seems to be nickel-plated brass (it definitely isn't steel because it's not magnetic). On a side note, I have a small GE alarm clock (probably 1960s or 70s vintage) where the blades on the plug are aluminium!! [Linked Image]

The rusted prongs on cord caps I've run across are American.

Joe Tedesco once posted a picture of a stump of lamp cord with one of those round rubber replacement caps and the pins were visibly rusted.

I haven't been able to find the picture (perhaps it was deleted). Maybe Joe can repost it? [Linked Image]

Don't have a digital camera, or I would take a pic of one or two of such old ones I've removed that I still have lying around at home.

Re: Why plugs with galvanized or copper-plated steel pins instead of solid brass or CU? #18586
12/12/02 05:01 PM
12/12/02 05:01 PM
L
Looee  Offline
Member
Joined: Feb 2002
Posts: 11
Willmar, MN, 56201
I know this really isn't about the material the plugs are made of, but does anyone know why plugs have those holes on the very ends of them?


Lee


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