Heat Shrink Tube Cutting

Selecting And Using Heat Shrink Tubing

Heat shrink tubing does exactly what it says it will: plastic tubing that can be shrunk to fit around any wire, cable, connector or circuit when making repairs or building electronic devices. It is chiefly made up of a polymer blend that has been exposed to cross-linking, and comes in a wide variety of colors, blends and diameters for a world of uses when needed.

Have a lot of rewiring or electronic maintenance projects coming up? Call us at Precision Tube and Wire today for a customized selection of heat shrink tubing that can make you job easier.

What makes it Different?

In order to expand the plastic while the tubing is being made, a process known as cross-linking is used to give the plastic a "memory". Cross-linking exposes the polymers to radiation, and creates what is known as a covalent bond between the atoms in the polymers. Once the process is over, the tube will remain in its fully expanded form until heat is applied. Once heat exchange is applied to the shrinkable tubing, it will return to its original form and diameter, sealing itself around whatever it is applied to.

Factors in Selection

There are always defining factors that must be considered when selecting any type of tubing. Besides the usual ones: temperature and voltage ratings, environmental uses, tensile strength, diameter and flexibility, shrinkable tubing adds a few more. When selecting this type of tubing for use, you must also consider sleeve diameter, shrink ratio, and shrink temperature.
Shrink temperature can be one of the most crucial factors to consider. If you are working with delicate electrical components, you definitely do not want to use shrinkable tubing that requires a temperature to activate that might damage the materials around the area you are working on.
Sleeve diameter relates directly to the diameter of the tubing before heat is applied. You want a snug fit after shrinking but you also want to be able to slide it freely over the wiring to be covered. The shrink ratio will give you an idea of how much diameter is lost when shrunk. For example, tubing with a ratio of 2:1 means that its diameter at purchase is twice the size it will be when shrunk, literally meaning that the final diameter is half of what it is at purchase.

Common Uses

The primary use for heat shrink tubing is in electronics. If you were to pop open any electronic device in your home right now, you will probably see first hand the many uses this tubing is put to. It is used to insulate a beadboard, terminals, connectors, and the wires themselves from dust, damage, and strain. No matter how large the bundle of wires, tubing can be found to fit. It is not only good for creating wire connections, it is also handy for any repairs that may be needed down the line.


Anyone who regularly works with electronics knows the value of good insulation, for any component. The extreme flexibility of heat shrink tubing cannot be beat for spot repairs or weatherproofing any electrical connection.