A Complete Guide to Heat Shrink Tubing

Heat Shrink Tubing is a versatile plastic layer which can be applied to cabling and components for several purposes by electricians, engineers and similar professionals, including:

• Electrical insulation - for example, to repair a damaged or exposed length of wire
• Protection – from dust, chemicals, moisture or abrasion
• Reinforcement – relieving the strain applied by cables held at tension
• Bundling multiple wires into a single unit
• Identification – the wide range of available colours allow for easy coding

They are also known as heat shrink sleeves, in particular when used with cables.

The name refers to the fact that the tubing is designed to shrink into place and become rigid when heat is applied, providing a durable, protective coating.

Given the range of possible uses, heat shrink tubing is available in a variety of materials, sizes and colours. Some also come with an adhesive liner to help the tubing stay in place once applied.

Watch out for the ‘shrink ratio’ – the relationship between the original size of the heat shrink tube and its shrunken form following application. This is usually either 2:1 or 3:1, with higher numbers indicating a greater ratio and therefore a tighter fit. For example, tubing with a 2:1 ratio will shrink to half its size and a 3:1 ratio indicates shrinkage to one third the full size.