I'm attempting to shrink wrap wire connections for the first time and I am wondering what size of heat shrink is needed for i.e. a single 22 AWG wire. Could it be any heat shrink tubing that fits the wire? Or is there a certain size that it shrinks to so that I must purchase one not too large? Thanks!

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    \$\begingroup\$ Do you mean heat shrink tubing perhaps? "Shrink wrap" makes no sense in this context. \$\endgroup\$ – Olin Lathrop Dec 17 '11 at 13:39
  • \$\begingroup\$ Yes.. heat shrink tubing.. \$\endgroup\$ – O_O Dec 20 '11 at 23:33

I have some typical 22 AWG wire here and 1/16", 3/32" and 1/8" diameter heat shrink tubing that has a 2:1 shrink ratio. In the not shrunk state each fits over the wire. In the shrunk state the 1/16" and 3/32" grip the wire firmly, but, the 1/8" is just slightly larger in diameter and slips. Don't forget that you may want a fatter solder join or two wires to be under the shrink wrap. For that reason my recommendation is to buy all three sizes. The stuff is not that expensive and it is good to have a good selection around.

You can buy a kit that contains several diameters like this for under $20:

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I got mine for $7 when it was on sale.

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    \$\begingroup\$ Having multiple sizes is a good thing. Sometimes when you're trying to cover something with some pointy bits, the tubing that's small enough to cover the wires will be visibly strained over the pointy places - in which case you can put a 2nd, larger diameter shrink tube over the first one. \$\endgroup\$ – JustJeff Dec 17 '11 at 14:27
  • \$\begingroup\$ $20?! I buy 4 ft lengths for less than 2 bucks each for 3/8th, smaller sizes are much less. There can't be well over 40 ft. in that package...I would think your nearest electronics wholesaler would have this, and it's probably even cheaper from some web based supplier. \$\endgroup\$ – mickeyf Dec 18 '11 at 6:16
  • \$\begingroup\$ @mickeyf: You seem to have ignored the price I actually paid, i.e. $7. I gave an approximate price range, why focus on the upper end? Also, The price of things depends on where you live. As a Canadian I always pay much more than what it would cost in the USA. Anyway, you are guessing what is in the pack, in fact there is 53 ft of stuff in here and it is organized well where 4 ft lengths are hard to organize. If I ignore the fact that you were estimating as you have done with me, your quoted $2 for a 4ft length makes the price $26. Obviously, I expect O_O to shop around for the best price. \$\endgroup\$ – Dave.Mech.Eng Dec 18 '11 at 16:54

I usually keep an assortment of sizes on hand just go with the snuggest fit. That's the practical technician method.

The formal engineering way is to pick the smallest standard tubing size that fits over whatever you're covering. Then make sure that the recovered diameter of the tube is smaller than the wire bundle coming in on each side to ensure a snug fit. Most heat shrink has a 2:1 unconstrained shrink ratio, but there is stuff out there that can shrink 4:1 if your application requires it.


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