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What type of metal are the tips of USB connectors/plugs typically made from? Aluminium?

I've noticed they will often, quite-easily, oxidise/rust/corrode.

voices
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  • Which part is "the tips"? Do you mean the electrical contacts inside the plug/socket, the metal shield, or something else? – gbulmer May 07 '16 at 03:50
  • @gbulmer The tips; the extremities, the points of contact/termination. (So both, I guess?) Admittedly, I assumed they would all be the same material. But obviously there is a bit more to it than that. – voices May 07 '16 at 03:57
  • Okay. I must admit, I have probably more than 100 USB cables, and I have never noticed rust or corrosion. The vast majority of my cables are full-size or full-size to mini USB. Is this a phenomena you've noticed on mini, micro or any USB? – gbulmer May 07 '16 at 04:06
  • @gbulmer Now that you mention it: Mini only, I think. Like the one often used by external USB WLAN interface cards and other small peripheral devices. – voices May 07 '16 at 04:12

1 Answers1

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Well, quick search at Mouser gives:

For this model:

enter image description here

And for this:

enter image description here

So I'd say stainless steel, some gold plated copper alloy(brass) and flame retardant plastic.

Wesley Lee
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  • The contacts themselves are made of brass. They are usually plated with gold. Sometimes, they are plated with tin to save cost. – Nick Alexeev May 07 '16 at 03:49
  • Very nice, cheers. I wonder why they plate it with a tin alloy; wouldn't it be better to just leave it stainless steel? – voices May 07 '16 at 03:51
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    @NickAlexeev brass is a copper alloy :P (added your info to the answer) – Wesley Lee May 07 '16 at 03:58
  • @tjt263 SS would be very hard to solder on PCBs – Wesley Lee May 07 '16 at 03:59
  • Is that a fact? @WesleyLee – voices May 07 '16 at 04:00
  • @tjt263 The shell needs to be soldered to the PCB for mechanical purposes. It's difficult to solder to "raw" unplated stainless steel. (If you have doubts, try to solder a copper wire to a piece of stainless using regular solder, regular flux, regular soldering iron temperature.) – Nick Alexeev May 07 '16 at 04:01
  • @tjt263 well, soldering SS = brazing, which is unsuitable for electronics – Wesley Lee May 07 '16 at 04:03
  • Interesting, I didn't know that. Is it to do with heat conductance? – voices May 07 '16 at 04:06
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    I believe not. I dont know but I'd guess its something to do with chemical bonding of different metals. Just a wild guess. – Wesley Lee May 07 '16 at 04:07
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    Not bad for a wild guess, stainless steel grows a protective coating of nickel oxide, tin plating provides a surface that's easier to solder to (the tin will dissolve in the solder). once the stainless steel is wet with solder air is excluded, and no nickel oxide layer forms. – Jasen Слава Україні May 07 '16 at 08:32