Here is a picture of a capacitor:


What are these two metal wires called in the professional world in the US?

  • The terminals, I believe.
    – Dan Bron
    Commented Oct 20, 2014 at 16:13
  • 3
    Leads, terminals, sometimes, believe it or not, simply "wires". "Pins", if the wires are reasonably stiff and cut short (for insertion into a printed circuit board). Outside of engineering spec documents there's no "grammar police" for this sort of stuff.
    – Hot Licks
    Commented Oct 20, 2014 at 22:03
  • That is a particular kind of capacitor, called an electrolytic capacitor. Electrolytics come in other packages, as well, including cylinders with the axial leads or at the ends of the cylinder. And for all you guys trying to call these wires "terminals" or "legs", please don't. A "terminal" is a fixed connection point to which you attach "leads". Only a complete amateur would call these "legs". Trust me, before I was a programmer I used to be a professional electronics technician. Commented Oct 20, 2014 at 23:41
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    This type of question would be good for the electrical engineering stack exchange.
    – Alex W
    Commented Oct 21, 2014 at 13:09
  • @Cyberherbalist: Although this is more of an electronics issue than an English one, axial leads come from the center of each end of a cap, along the axis of the cylinder. Leads which are equidistant from the center, along different radii, are called "radial".
    – supercat
    Commented Oct 21, 2014 at 15:32

7 Answers 7


The pieces of wire are called leads. I've never heard them referred to as "legs" except in casual conversation. For more information, Wikipedia has a pretty comprehensive article:



Engineers typically use “leads”, pronounced like “bleeds”.

  • 4
    Which is what happens when you stick your hand with one of them.
    – Hot Licks
    Commented Oct 20, 2014 at 22:02
  • Said Hot Licks... Commented Oct 20, 2014 at 22:54
  • 2
    "leads" rhymes with bleeds, but is not pronounced like 'bleeds' - or, it's pronounced like 'leeds'. This might seem obvious and a pedantic nitpick, but a non-native speaker may not find it to be obvious and that there should be a 'b' sound in there.
    – Johnny
    Commented Oct 20, 2014 at 23:12
  • Please expand on this answer as it's a duplicate of the accepted (older) answer.
    – SrJoven
    Commented Oct 21, 2014 at 0:54
  • what the? This should not be an acceptable answer, it is misleading. We certainly do not say "bleeds", not even as a joke.
    – KyranF
    Commented Oct 21, 2014 at 9:09

Let me summarise the various answers here.

In engineering school and then later at a manufacturing plant, we called them leads.

Terminals are used when having to describe the leads in terms of electrical polarity +/-.

Legs are used by lay-people.


Collectively, they're often figuratively referred to as legs - on a standard transistor, the three types are are called the Emitter, the Base, and the Collector, but that's probably more information than you needed.

  • 1
    Providing the names used on a typical bipolar transistor in a question about capacitors is just confusing for people looking for information without the knowledge to distinguish what you are talking about. Also just stating "transistor" when other names are used for what the leads connect to on other types of transistors is further confusing to people looking for information about capacitors.
    – Makyen
    Commented Oct 20, 2014 at 21:29
  • 1
    @Mayken, I've never seen a "bipolar transistor"! Can you treat the condition with some kind of electrical stimulation? Commented Oct 20, 2014 at 23:32
  • @Makyen: If OP is asking for "capacitor-specific" terminology, I'd say it's an Off Topic domain-specific question that should be addressed on electronics.SE. Ditto when it comes to identifying/distinguishing the individual terminal names for transistors, capacitors, IC's, or whatever. I still think Anglophones in general call them legs, and it's effectively irrelevant/OT for ELU what electrical engineers call them. Commented Oct 21, 2014 at 12:58
  • @FumbleFingers: I would agree that the question borders on being off-topic. My point to you was that throwing in specific names for the leads of a type of device which was not pictured is counter productive. This is particularly true when implying the names provided apply to transistors in general when they apply to one type of transistor, not all, or even most [most depends on if we are counting only single transistor packages, or including all transistors made]. While the question did state "in the professional world in the US", I do not contest that legs is a valid response.
    – Makyen
    Commented Oct 21, 2014 at 15:23
  • @Cyberherbalist: :-). Nice. If you are interested, Wikipedia has a good description of different types of transistors.
    – Makyen
    Commented Oct 21, 2014 at 15:27

You can call them leads or pins.

  • 1
    Welcome to EL&U. Your answer would be improved by linking to definitions from a reference or providing examples and explanation of the usage. I encourage you to visit the help center for additional guidance.
    – choster
    Commented Oct 21, 2014 at 0:43

As @dan-bron commented, 'terminals' would be valid, though the main term I've hear them referred to by would be just 'legs'. 'Electrodes' or 'conductors' would also probably be acceptable depending on the context.


Collectively, and generically, in the professional world the wires are called leads. As has been mentioned, Wikipedia has a decent article on Lead (electronics). Quoting the first sentence of the Lead article:

In electronics, a lead is an electrical connection consisting of a length of wire or metal pad (SMD) that comes from a device.

Individually, the lead (wire) near the - (negative) mark is connected to the cathode of the capacitor and that lead is called the cathode (this is the shorter wire). However, it is much more common to use a term similar to "the negative lead".

The lead (wire) that is not marked with a - sign connects to the anode of the capacitor and is called the anode (the longer wire). On some capacitors the anode is marked with a +. For this lead, it is much more common to use a term similar to "the positive lead".

Technically, the wires are both leads that connect to the capacitor's anode or cathode, not the anode or cathode themselves. However, that distinction is not usually made.

Wikipedia has a long article on Capacitors.

  • Not one EE in ten could tell you (at least without having to think about it and maybe draw a picture to remind himself) whether it was the cathode or the anode that is "positive".
    – Hot Licks
    Commented Oct 20, 2014 at 22:04
  • True, but they will often be labeled as such in diagrams and specification sheets received from manufacturers. However, I would say that the significant majority of EEs would know that the technical terms for the positive and negative leads are anode and cathode, even if they would have to at least think about which is which. Saying "the negative lead" or "the positive lead" would tend to communicate more effectively. Thanks for the comment, I added the clarification to the answer.
    – Makyen
    Commented Oct 20, 2014 at 22:11

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