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04.05 Heat Shrink Tubing

Heat shrink tubing is usually made of PVC or Polyolefin. Polyolefin is generally a better material and has a longer shelf life since it is less effected by temperature fluctuations in storage.


Heat shrink tubing has a variety of uses that include:

  • strain relief
  • electrical insulation
  • wire bundling
  • wire labeling
  • wire color coding
  • cable protection

Shrink Ratios

Heat shrink tubing has a shrink ratio, meaning how much smaller from its original size does it shrink to. A tube with a shrink ratio of 2:1 will shrink to half its original size. A tube with a shrink ratio of 3:1 will shrink to a third of its original size.

Adhesive Lined

Some heat shrink tubing has adhesive on the inside. This is common in marine applications and in other harsh environments. This help secure the wire to the tubing and prevents water and other contaminates from entering under the tubing. Heat shrink tubing with adhesive is often found on crimp terminals to help with sealing.

How to Use

  1. Slip the heat shrink tubing over the wires or component. Make sure to put the tubing on before attaching large end pieces or connectors that the tubing may not slip over.
  2. Put the tubing in position.
  3. Use a how-to-use-a-heat-gun to apply even heat all around the tube until it completely shrinks. Take care not to overheat other objects nearby.
  4. If using adhesive lined tubing, make sure all of the adhesive melts evenly.