Wire Quality

[Legion]

I was about to pick up some rolls of wire. I'll be using this for small "learning electronics" type projects. When I looked on digikey prices ranged from about $15 - $50 per roll (for the same gauge and core type, just a different brand). A local place is offering it for $9 per roll. With such a wide disparity in pricing I was wondering if there's a difference in quality I need to be aware of, or are they all essentially the same?

In case it matters, I was looking to get:
20 gauge stranded red jacket
20 gauge stranded black jacket
20 gauge solid red jacket
20 gauge solid black jacket
22 gauge stranded red jacket
22 gauge stranded black jacket
22 gauge solid red jacket
22 gauge solid black jacket

[GiveMeTheJuice!]

how much the merchant paid for the wire is one of a hand full of reasons why the price varies so much. The merchant may have bought when copper was at a higher price. But maybe not. Ask the merchants why, they should tell you why.

[PedroDaGr8]

It's not surprising. Wire has always had a variety of prices for what appear to be similar stuff. It's hard to SEE things like breakdown voltage of the insulator, flexibility, etc. Plus there are some manufacturers that just plain charge more for the name. One trick that IS common is that some quote the AWG of the copper and others quote the guage of the copper + insulator. Others quote both. This is very common in larger gauges but is also an issue in the smaller gauges as well.



As you can see they all have the same outer diameter but varying amounts of metal inside.

[mariush]

Diameter of each strand, how many strands, if they're tinned or not, how thick the insulation is, the insulation rating, if it has those chemicals that make it not kill you when it burns or makes smoke, or if it self extinguishes or not to some degree... some even have some anti-animal chemicals in them (to make them less "tasty" to rats and squirrels)

For thinner cables (higher gauge) there's also the issue of making sure it's real copper or if it's copper clad aluminum (aluminum with a thin coat of copper, lots of cheap network cables are CCA)

[CaptnYellowShirt]

Buy used rolls on eBay.  I stress the word 'used'. Don't get crappy china brand stuff. Get the last 50ft of a roll of good digi-key brand stuff that a guy doesn't need for his project any more.

[nanofrog]

Buy used rolls on eBay.  I stress the word 'used'. Don't get crappy china brand stuff. Get the last 50ft of a roll of good digi-key brand stuff that a guy doesn't need for his project any more.

       

Please, stop giving away the golden secrets!   

In all seriousness though, this is excellent advice so long as it's not overpriced. 

[JoeN]

I'll be using this for small "learning electronics" type projects.

What kind of small projects, mid-power audio amps?  20 and 22 gauge is pretty serious if all you are going to do is work with microcontrollers, FPGAs, switches, LEDs, LCDs, VFDs, etc.  I mostly use 26 gauge solid wire.  Try running a bunch of 20 gauge wires from a microcontroller to a many-pin LED matrix, you will quickly run out of room.

[Legion]

I'll be using this for small "learning electronics" type projects.

What kind of small projects, mid-power audio amps?  20 and 22 gauge is pretty serious if all you are going to do is work with microcontrollers, FPGAs, switches, LEDs, LCDs, VFDs, etc.  I mostly use 26 gauge solid wire.  Try running a bunch of 20 gauge wires from a microcontroller to a many-pin LED matrix, you will quickly run out of room.

More basic than that. RC Circuits, diodes, transistors, etc. Nothing "real". Just small circuits that illustrate concepts.

[JoeN]

More basic than that. RC Circuits, diodes, transistors, etc. Nothing "real". Just small circuits that illustrate concepts.

You may certainly use smaller gauges than 20/22 for that type of thing, if you care to.  And stranded wire makes no sense for that type of project, though you might want it for power cords later on

[edavid]

As usual, the person asking a purchasing question doesn't give us a clue where in the world they are located.

Anyway, if you are going to pay full price for wire, avoid the crappy PVC insulation that burns and shrinks when you solder the wire.  "UL 1061" wire has really nice heat resistant insulation, that is much easier to strip than teflon.  I don't know if it has a different name outside the US.

On the subject of cheap wire, we used to ask Bell Telephone technicians for wire, and they were always happy to hand out end rolls.  I guess the modern equivalent is to ask telecom installers for cross connect wire, or CAT5 cable scraps.

If you are in the US, and you have a Habitat for Humanity Restore nearby, you might look there for wire.

[CaptnYellowShirt]

I guess the modern equivalent is to ask telecom installers for cross connect wire, or CAT5 cable scraps.

If you are in the US, and you have a Habitat for Humanity Restore nearby, you might look there for wire.

Dumpsters. I find that stuff all the time. Especially if you can see a building is being renovated.  It's common practice where I live for the contractors just to gut the structure -- wires and all. They typically come out in a big (like 2ft) yarn ball of cable so make sure to bring your snips with you.

[SeanB]

Just take the whole ball and sort it later.

[CaptnYellowShirt]

Just take the whole ball and sort it later.

Typically you'll find a single 2x4 wrapped up in the ball... and typically that 2x4 is wrapped up in the rest of the dumpster.

[SeanB]

You are not strong enough to break a little bit of wood? I managed to fit a complete rack unit in the back of the van, even though it was about a half meter too long. A little bit of persuasion and it sort of fell apart. Luckily the destination was the scrapyard, it went in in some bent pieces. Tore the metal apart by hand and by using leverage and feet.

[CaptnYellowShirt]

Were you driving one of these?

[SeanB]

Were you driving one of these?

No, I drove some of it's cousins. You really do not want to be inside one in that final test. Friend of mine was involved in an accident in an APC that went off the road on a bridge. Still has back problems from the drop into the river below. the one thing they do not show there is that you really do not want to change a tyre but that it runs well enough with the run flat rims it has. Also the fuel tank is 80 gallons, and will empty like you have a drum pouring out onto the ground. The steering is heavy even with power assist, the AC is not an optional extra even in the Antartic and it handles like the truck it is. Spares can be a tad expensive. Top speed is best described as you will never get a speeding ticket. Plus is speed bumps are not a worry until they are Jersey barrier size.