Best flexible hook-up wire options

[larry42]

Looking for general purpose hook-up wire, (26AWG and approx. 34-38AWG) for attachment to SMD pads for measurement and board-board.

1. I typically use 0.1 or 0.2mm ECW (enamelled copper wire), but would prefer a *stranded* solution with some insulator.

2. For the 26AWG wire i have been using stranded mPPE wire - but the insulation is too stiff - any non-PVC alternatives?

Any recommendations for the above?

Am professional - so don't need (don't want) cheap/fly-by-night Ebay links, as I want to ensure availability over time and necessary MSDS datasheets.

[PA4TIM]

I just wanted to start a similar topic. I need it for the same reason and also professional. Tried the same things (CU wire and thin teflon multistrand).
I was thinking about using wire-wrap wire but I can not find it on the Farnell site and I have no experience with it. As far as I know it is isolated but you do not have to strip it. That sounds good but I'm only afraid that the isolation will melt to far when you solder it. I do not want to cause shorts.

Just a tip that may be useful:
I often solder all test wires to a header and I have made a "system" that makes it easy to connect scopes, DMM, LA's etc to those headers. I often attach the header to the DUT so there is no mechanical stress on the wires.
 A video I made about the "system" :
 https://youtu.be/MtMTyAKju9s

[d-smes]

For stranded wire, I've seen pictures of silicone insulated wire and it's claimed to be quite flexible.  See https://www.adafruit.com/?q=Silicone%20Cover%20Stranded-Core%20Wire which should return #26 & #30 AWG sizes.  It looks bulky, which is to be expected with 600V rated insulation.  I've not used any myself nor looked to see if other distributors carry full reels traceable back to manufacturer.

[tooki]

I’ve bought various gauges of stranded silicone wire from digi-key. They have a huge selection (though it dwindles below 24ga), and it’s actually no more expensive than eBay. (eBay’s only advantage in silicone wires, IMHO, is that they carry a wider selection of colors.)

Bear in mind that, as best I can tell, silicone insulated wires fall into in 3 general categories: “normal”, high-voltage, and test lead wire.

Test lead wire has the finest strands, making it much more flexible (and more expensive) than the others, and generally thick insulation to make it more durable, since it’ll be used naked, so to speak. (For reference, on 18ga, outer diameter will be 3-3.5mm.) Many manufacturers now make the insulation dual-layered (white inner layer and colored outer layer) on all but the smallest gauges, to make wire damage easier to spot. In my last Digi-Key order, I got some thicker (18ga I think) wire from Pomona and Mueller, and some thinner (24ga I think) from Cal-Test. It’s all nice stuff. (Oddly, despite it officially being the same stuff, the Pomona wire still isn’t quite as flexible as the wire on my Fluke TL175 probes. Differences in batches I suppose...)

High-voltage wire is, well, made for high voltage applications. I have no experience with this, but I assume it’s got really thick insulation or something.

The “normal” silicone wire is just that: ordinary stranded wire with silicone insulation. It’s more flexible than PVC or Teflon insulated wire, but not as flexible as test lead wire. But the insulation is thinner, so not as bulky, but not suited for uses with a lot of mechanical abrasion. So perfect for bodge wires and the like. (For reference, on 18ga, typical outer diameter around 2mm.)

The Adafruit 30ga silicone wire falls into that category, and it’s neat stuff. It’s very, very thin: The outer diameter is extra-thin 0.8mm (similar to a mechanical pencil lead, for reference), so I’d hardly call it bulky, unless compared to teflon or lacquer insulation. Unlike how I expected wire that thin to act, it does not behave like limp thread: it has some memory. If you shape it, it will retain the shape to an extent. For some appications this is helpful, for others annoying. Digi-Key carries it, by the way.

(I haven’t tried the 26ga.)

Digi-Key also carries a full range of silicone wires down to 30ga from a brand called Daburn, but it’s special-order by the reel only. But it’d do better for your application as far as traceabiity. (Their 30ga is 1.1mm outer diameter.)



What I would love for the big distributors like Digi-Key to carry is specialty earphone cable. It’s thin and super-flexible. (And, granted, a pain in the ass to solder. But I digress.)

[grifftech]

for the 26AWG go to your local thrift store and get a printer cable, many different colors inside

[tooki]

for the 26AWG go to your local thrift store and get a printer cable, many different colors inside

You didn’t really read the requirements at all, did you?

[Neomys Sapiens]

One thing that one has to keep in mind is that the wicking effect gets more severe with very fine stranding.
Test-lead fine should be soldered with a heat-sinking tweezer or equivalent close to the solder joint in order to prevent solder from creeping up the wire, thereby leading to breakages.

There is a reasonably flexible type of ETFE/PTFE isolated hookup wire, which is known as Raychem Spec-55.
It is one of the subtypes of MIL-W-22759. Other thin-walled subtypes have similar properties.
There is also a ETFE/PTFE isolated wire with test-lead like flexibility, which makes it also well suited to repeated motion. Also by Raychem under the designation Spec-99, but they might deny availability or may have lost knowledge about. Probably not under standardisation, but competitors of Raychem/TE might have similar product (Habia, Petsche, etc.,) so maybe ask for equivalent.

[Someone]

I’ve bought various gauges of stranded silicone wire from digi-key. They have a huge selection (though it dwindles below 24ga), and it’s actually no more expensive than eBay.

As you expand on there is a wide range at digikey with the high stand counts suitable for test leads and movable connections.

For finer wire probing SMD parts or through fine seams in equipment the wire wrap style reels are almost perfect, the keyword for the insulation is Polyvinylidene Fluoride (PVDF). At the small diameters it only comes in single conductor options so its best to glue the wires down and support them, avoiding flexure on any sharp bends or joints then its reliable enough to leave in place while working on a design. Terminate the other end into 0.1" headers or test hooks suitable for connecting onwards to test equipment.

[calexanian]

I tend to use Irradiated PVC wire. I know you mentioned staying away from PVC but the non melting chartachaeristics and ease of stripping make it my go to. We buy from

http://www.weicowire.com/index.php?route=product/category&path=184_50_52

They also have the specialty wires too. Kynar, silicone rubber test lead, etc. And also Magnet wire.

[Neomys Sapiens]

Then of course, the Wires coming under MIL-W-81044 (CROSSLINKED POLYALKENS , CROSSLINKED
ALfMNE-IMIDE POLYMER, OR POLYARTLENE INSULATED) and those with a EPDM or crosslinked Polyolefin insulation under MIL-W-16878 provide some nice alternatives to ETFE/PTFE.

Hint: when accsessing those specifications (DAPS/ASSIST), go directly for the supplement S1, which shows the various make-ups covered by it (slash sheets: MIL-W-xxxxx/yy, with yy identifying a definite type).

There are also classic wiring materials of astonishing properties: I have some rolls of both solid and stranded wire covered by a varnished spun isolation (silk or glass?), with the solid wire partially having a underlying varnish coat, which have very good long term stability and graceful degradation behaviour. But I would not use them where any motion is involved.

The Huber&Suhner Radox wires (crosslinked polyolefin) are also clearly superior to PVC and are somewhat more widely available.