Question about heat shrink tubing

hi there,

when choosing heatshrink, generally the sizes indicated are lay-flat sizes. ie: if you were to push the tubing flat on a surface and measure end to end.

to work out the size you need there is a formula: diameter x 3.1416 x 0.5 that and you will use the size nearest to that. for example: ( i am going to use millimeters in this example, as i am unfamiliar with imperial) say you have gathered that the OD needed to fit over your fan cable lead is 10mm - you would work it out like this 10 x 3.1416 = 31.416 x0.5 = 15.07 --> you would choose the nearest size to that in metric the closest available size to that is 19.0mm which is 0.75". (3/4 inch?)

the general shrink ratio of heatshrink is 2/1 ie it will shrink to 1/2 its size, although there are others available with higher ratios, up to 4/1.

be sure to check with your supplier if the sizes are lay flat or internal diameter to avoid a nasty surprise when it arrives!

hope this helps a bit

You could get a variety pack with different sizes. Try Radio Shack or an auto parts store.

How can I determine the diameter of a particular cable? Also 2.54 cm is equal to 1 inch. So 1.507 cm is equal to 0.593 inches.

just a thumbsuck! have a look and measure with a ruler and use your best guess as to what size will go over it, if you can sort of get a rectangular measurement ie: length and width, you can also work it out, eg: L = 10mm, W = 5mm the formula is L+W x 2 / 3.1416 so it will be 10+5= 15, 15 x2 = 30, 30 / 3.1416 = 9.54mm --> you would then use the next size up.

because it has such a high shrink ratio you dont have to be exact, just ball park, because it will shrink down quite a lot. you should always go a bit bigger for safety anyway.

as rsmith said you can get a mixed set from a radio shop, although it will probably be black, not those uv colours. the best bet would be to go to an electrical wholesaler, they can show you samples, will cut it to your specifications and will probably have a few colours, usually red, blue, green, yellow and white. if you are looking to put it over a large plug, like your 24pin power connector they may have some with the higher shrink ratios.

do you have a hot air gun?

I picked up a couple assortments of black heat shrink.

I believe so. I heard lighters work too.