Banana connector types

banana connector is a single-wire (one conductorelectrical connector used for joining wires to equipment. The term 4 mm connector is also used, especially in Europe,because the pin’s diameter is nominally 4 millimetres (0.16 in).The pin has one or more lengthwise springs that bulge outwards slightly, giving the appearance of a banana.

The original plug consists of a cylindrical metal pin about 20 millimetres (0.79 in) long.However other sizes have emerged, such as 15 millimetres (0.59 in) pins, which can commonly be found in the US. Banana plugs and cables are typically rated for 30 V at 15 A, but there are versins rated up to 30A. Typical applications are test cables on electronics laboratories and speaker connections on HiFi systems.

Banana plug connected to power supply:

In most European countries, the standard mains power receptacle will physically accept banana and even US-style “double banana” plugs (the standard US pin spacing of 3/4 inch (19.05 mm) is close enough to the mains plug spacing of about 19 mm, and the pin diameter is also compatible), leading to a risk of electrical shock.

A typical design is now required (IEC 61010) on digital voltmetertest leads and several other measurement and laboratory equipment. In this design, the metal banana plug is entirely sheathed in plastic and presses into a deep recess in the DVM. The sheathed male plug will not work with an unsheathed female socket, but an unsheathed male plug will fit a sheathed female socket.This kind of sheathed banana connectors are typally used up to 1000V voltages.

Last but not least: Screw locking Banana.The UHF connectoris a threaded RF connector design RF connector  useable up to 100 MHz (typically used for HF and lower VHF frequencies). Thsi connector has approximately 0.156 inch (4mm) diameter pin and socket for the inner conductor. It is possible to mate UHF connector female with banana plug.


  1. Tomi Engdahl says:

    Tip – Banana Plugs into AV Amp Speaker Wire Binding Posts

    How to attach speaker wires with banana plugs into Amps that use binding posts.


    Wow, never knew that about the lugs inside the posts.

    Very useful post. Thanks very much. I thought I was going nuts – and starting to swear – until I thought let’s search on t’internet and up pops you with this gem !

    Why do the manufacturers even bother to put those plugs in at all? It’s inconvenient for the consumer and adds a small cost to the manufacture.
    …so why do they have those caps in???

    It has to do with EU regulations, the posts have to be made so they don’t accept a regular power plug, which in the EU is the same size as a banana plug.

    “EU health and safety” gone crazy rules though

    In the EU using banana plugs in consumer electronics is illegal. They can be connected to our mains wiring socket since the spacing and the hole diameter happens to be the same. So as a precautionary measure they’re plugged as such and if you remove them, it’s on your own responsibility. (and this was after a bunch of people were killed by goofing around with banana plugs not knowing what goes where)

    If it was mentioned in the manual how to remove them, the manufacturer would be breaking the law.

  2. Tomi Engdahl says:

    EEVblog #1052 – BEWARE Crap Banana Plugs!

    Trap for young players, beware of crap quality banana plugs!
    Dave discovered his gold plated rotating spring leaf lantern style contact banana plugs are craptacular!

  3. Tomi Engdahl says:

    Why are banana plugs prohibited in Europe?

    Bought an Onkyo AV receiver today and while looking in the manual section for speaker hookup it told you how to use banana plugs but it also mentioned that banana plugs are prohibited in Europe? Why is that?

    They are not legal for use in europe because they can be plugged into a wall outlet!! WBT makes a european legal type and it has an extra plastic pin to keep some chucklehead from plugging it into mains voltage.

    European electric wall plugs are round, and the same size of a standard banana plug.

    Yes we in the UK were not too happy about this as we have a totally different (and I may add far superior) power socket and plug setup with square pins and also the socket has a covering mechanism that only opens up access to the live and neutral points once the longer earth pin has gone in. This saves a baby sticking a knitting needle in the live socket etc. Oh and it has a proper fuse as well. Apparently the eurozone is always hinting at making us switch to their lower standard but if you visit say France or Spain all you see is euro sockets hanging off walls with wires on show.

    My excuses, though my point still stands… an UK/US installation is more likely to burn than an EU installation.

    That’s why you use normal banana plugs for audio / low power outlets and the legal ones for high power outlets and labs.

    Oh and btw… your multimeter plugs can ONLY be used for measurement purposes.
    Don’t try to run high currents trough it! they might ‘ seem’ safe because of the plastic tube but they’re in the best case made from silicone-rubber or lower quality isolation. Heat it up and it’ll melt.

    Banana plugs “for use in U.S / Canada only”

  4. Tomi Engdahl says:

    Incidentally, aside from US power sockets which have flat connectors, banana plugs would fit into pretty much every power socket in the world, as they all have round holes.

    I’m an electrical engineering student in Greece, and i use this plugs all the time in labs.

    The joined banana plugs are the same size as the AC wall outlet size. My UK built speakers have connectors which will accept banana plugs but not joined due to spacing.

    They’re sold everywhere, not banned.

    When you buy speakers or amps the openings for banana plugs are plugged with some plastic. But it’s usually very easy to get the plastic out and just use banana plugs.

    This is hilarious, what could possibly be the reason? Prevent people from plugging their speakers into a generator?

    I’m sure it’s an enforcement issue. As in: the regulation is too stupid to enforce :)

    Returned to HiFi – banana plugs banned in EU!

    Sooooooo, after many years away from HiFi, I’ve just found out that banana plugs are banned in the EU. The brand new amp and speakers I’ve just bought, thankfully, were able to accept my banana plugs for the speaker cables after I popped out the blanking pins.

    Wonder if its because the plugs fit pathetic euro mains sockets? The eu should ban all metal pointy things. And bananas.

    A quick google reveals that this has been around since at least 2008. Basically, the twin banana plug’s spacing of 3/4 inch is very close to the 19mm of the continental 220V power outlet, so that it is easy to insert the twin banana plug into the power socket. Since amps also have power leads, the possibility of confusion is quite real.

    UK have a different plug socket.

  5. Tomi Engdahl says:

    Europe and Banana plugs. What’s up with that?

    Yes, that’s it pretty much.. banana plugs that can go into mains outlets and they even insist on covering binding posts on high power amps if the output voltage is high enough.

    Doesn’t it warm your heart to know the government cares about your safety so much?

    I believe that’s pretty much it… Just like if somebody wanted to use a 110 outlet for an amp output here in the US…
    …and a little more. Anything that carries more than 25Vac or 35Vdc must be protected so you can’t touch it. With banana plugs, there is always the risk of them not being fully plugged-in, leaving bare metal.
    Most A/V amps come with bananas because they’re less than 80W per ch into 8ohms, but they come with a plastic thingy plugged-in, so a kid can’t touch the metal with his 5mm fingers ??? .
    Officially you’re supposed to use bare wires or fork connectors (personally I think there are more risks of touching the conductors, but what do I know?).
    Practically, you take off the plastic thingies and use banana plugs. Who will enforce the regulation?

    I have to agree, re: bare wires. A billion amp channels have been destroyed by bare wires shorting.

    the banana plug will fit into a Euro style 230volt outlet. imagine the problems that could cause, both firehazard if plugging a speaker into the wallsocket, the danger to any person trying such things and other possible problems

    Funny thing is, here in the US we have the practice of installing the mains outlets oriented so that they look like faces. This is incorrect according to the building code. I install mine with the ground prong on top, and people will spot it right away and puzzle over it. The idea is that if the plug does not seat all the way, and something conductive falls across it, it’s safer to have the ground up top. Never had anything fall that way, but there’s no downside to doing it like that – if you don’t count puzzled looks.

  6. Tomi Engdahl says:

    …that the use of banana plugs is banned in all IEC-compliant countries.
    Is this true? What is the rationale?

    That’s exactly it – in some European countries banana plugs, are the same plug as used in AC outlets and worse yet, the “stereo pair” spacing was exactly the same.

    This is why audio makers had to alter their post spacing a few years back if they accepted bananas, so that kiddies wouldn’t plug the speaker cables into the wall.

  7. Tomi Engdahl says:


    Banana plugs

    These once ubiquitous speaker connection plugs slot into the binding posts found on most speakers. The problem? They also fit quite easily into European power outlets, which led to them being banned on new equipment.


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