When to use heat shrink tubing

When to use heat shrink tubing

Heat shrink tubing or electrical shrink tubing is an integral part of any electrician’s toolkit. Here, we look at what it is and when and how you should use it.

What is heat shrink tubing?

Heat shrink tubing is thermoplastic tubing that shrinks down when a heat source is applied to create a secure seal.

How does heat shrink tubing work?

Once a heat source is applied to the tubing, it responds by collapsing radially, creating a protective and tightly sealed layer around the contours of the wiring.

When to use heat shrink tubing

Used mainly by electricians and engineers, heat shrink tubing is used for electrical insulation. It can be used to protect exposed wires after they have been repaired, from further damage, and it can be used to reinforce cables held at tension. Additionally it offers protection against penetration from dirt and moisture.

What is heat shrink tubing used for?

Heat shrink tubing is used to insulate and preserve products as it is extremely resistant to moisture, dust and dirt, and abrasion. Consequently, electricians and engineers commonly use heat shrink tubing in a number of applications including, but not limited to:

  • Cable jacketing
  • Covers on temperature probes
  • Roll covers
  • Chafing sleeves
  • Light duty bearing surfaces
  • Electrical insulation for wire bundles

Types of heat shrink tubing

Heat shrink tubing is available in different shrink ratios, which refer to how much the tubing must shrink to fit the narrowest part of what it will be covering. You can have a shrink ratio of 3:1 (the tubing shrinks to a third of its original size) or 2:1 where the tubing will shrink to half its size. Adhesive lined heat shrink tubing is also available.

Alternatives to heat shrink tubing

The unique characteristics of heat shrink tubing means that while there are other products that can be used in its place, perhaps as a temporary measure, there is nothing that will exactly replicate what heat shrink tubing does. Electrical tape will serve the same purpose but will eventually lose its adhesiveness and is less resistant to chemicals and abrasion.

How to use heat shrink tubing

  • Choose heat shrink tubing with a sufficient shrink ratio that the tube will fit around cables before applying heat – this will ensure a tight fit is achieved once the heat has been applied. The tubing will shrink in length too so make sure you have a long enough piece.
  • Cover the area by sliding the tube over it
  • Apply heat evenly with a heat gun, working from the middle out to reduce the risk of bubbles forming. Do not rest on one area, but keep the heat source moving to avoid charring the tubing and making it brittle. NEVER use a naked flame such as a lighter – this will cause uneven shrinkage and will compromise the insulation.
  • Once the tubing has been applied, allow it to cool completely before applying any pressure. 

Heat shrink tubing from cableties-online

At cableties-online our heat shrink tubing is offered in a 2:1 ratio and our adhesive lined heat shrink tubing in 3:1. We also carry large stocks of other electrical supplies including cable sleeving, conduit and spiral wrap, and terminals and connectors.

For all enquiries please email us at sales@cableties-online.co.uk or call our friendly team on 01623 412160.