I have a pile of stranded breadboard wires, but need to buy or make more. The red one on the left have a solid metal pin, a molded plastic barrel, and stranded wire, and was purchased at Amazon. Most of the stranded jumper wire sets appear to be more or less identical to that.

The blue one on the right also has a solid metal pin, but the black part seems like heat-shrink tubing.

I'm having a hard time sourcing the metal pins. It is easy enough to find square pins intended for various connector systems, but I don't know how to search for the round ones.

My end goal is to build a small quantity (dozens) of jumpers for my own use. I can fall back on buying more from Amazon, but the molded plastic smells terrible, even after weeks of outgassing.

Breadboard Wires

Edit: Related question. The closest answer to my question is a suggestion for Molex crimp-on pins. Those are close, but not quite what I'm looking for.

  • \$\begingroup\$ Shopping questions are off-topic, and should be closed. \$\endgroup\$ Commented Feb 21, 2012 at 22:28
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    \$\begingroup\$ Use the squared pins, I don't see the problem. They should fit in the breadboard. \$\endgroup\$
    – clabacchio
    Commented Feb 21, 2012 at 22:32
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    \$\begingroup\$ @LeonHeller Yeah, this isn't a shopping question. This is a parts sourcing question. I'm not asking for a recommendation on a particular product, I want to know what the part is called. \$\endgroup\$ Commented Feb 21, 2012 at 22:47
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    \$\begingroup\$ @LeonHeller I don't think this is a shopping question at all. It falls in line with all of our component identification questions. In fact here is one very similar to it: electronics.stackexchange.com/questions/11398/… only difference is that question was asking about the whole wire, not just the ends. \$\endgroup\$
    – Kellenjb
    Commented Feb 21, 2012 at 23:20
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    \$\begingroup\$ For small or large quantities,m mking you own jumper-wires is going to be a lot more expensive and time consuming. Commercial jumperwires are made cheaply in bulk; if you don't like the amazon ones, look for another supplier. Try Maplin or Adafruit? \$\endgroup\$
    – Chris2048
    Commented Apr 29, 2012 at 11:43

1 Answer 1


Those are very long, but in general what you are looking for are (at least colloquially) called
machine tooled pin headers

"Machine-Tooled" generally means it's made with something along the lines of a screw-machine. It's a machining process, rather then a stamping process, as is common for rectangular pins. However, it also means they do cost more.

Off the top of my head, I know Mill-Max makes them, but they are fairly expensive (mill-max is high-end/mil-spec. On the other hand, 1 strip of 40 pins may be ~$5, and considering that would make 20 jumpers, cost may not be too big a deal.

enter image description here enter image description here

I would imagine that other companies make similar parts, but I don't know them off the top of my head.

Digikey carries at least some varieties of them: enter image description here

The place to look is the "Rectangular - Headers, Specialty Pin" category.

It's also possible the jumpers are manufactured using the pins from some connector, without the actual connector housing. In this case, you're on your own. I don't think there are really any resources for looking up connectors by their pins.

However, the magic words here are again "Machine Tooled". Machine-tooled pins are the round variety (e.g. they are machined, not stamped or moulded).

  • \$\begingroup\$ Are they not seriously fixed in that plastic base so you can't easily get the individual pins out? Even if you can pull them apart, it this seems to be suboptimal for jumper cable endings. \$\endgroup\$
    – Sz.
    Commented Dec 31, 2015 at 20:58
  • \$\begingroup\$ @Sz -- The pins are easily removed from the header plastic by carefully cutting the plastic with a flush cutting diagonal cutters (commonly used to trim component leads after soldering to PCB). I use these all the time for prototyping to be able to swap in different value components. \$\endgroup\$
    – scanny
    Commented Feb 29, 2016 at 21:31

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