Heat Shrink FAQ's >>>


Heat shrink tubing does exactly what it says on the tin; it is an expanded piece of plastic tubing that is designed to shrink in size when it comes into contact with heat. Heat Shrink Tubing is an incredibly versatile material can have many different uses, and is particularly found within electrical, industrial and telecommunications environments.

Whether you need to insulate cables that may be exposed to extreme conditions, or you just need to colour code your wires for easy identification, heat shrink tubing is the ideal solution. It is affordable, easy to install, and can be used just about anywhere.

Heat Shrink Tubing Ratios

Heat shrink tubing comes in many different forms, and it is important that you select the right type of heat shrink tubing for your needs. Every type of heat shrink tubing has its own shrink ratio; this will tell you just how much the tubing will shrink when it is heated.

For example, heat shrink tubing with a 2:1 shrink ratio will shrink down to half of its expanded diameter; tubing with a 3:1 shrink ratio will shrink to a third of its original size, and so on up to a 6:1 shrink ratio.

For all of your heat shrink tubing needs, you should look no further than right here at Hilltop Products. As you can see, we have plenty of different heat shrink tubing products in stock. Please feel free to take a look through the complete range of heat shrink tubing that we have on offer by using the links provided.

How To Select The Correct Size Of Heat Shrink Tubing

(for more detailed help refer to the new heat shrink sizing guide)

Heat Shrink Tubing Vocabulary

I.D. - Inside Diameter

The Inside Diameter of the tubing is measured in inches (in.) or millimeters (mm). Measure the open inside circle. Do not measure the tubing when it is flattened.

Expanded I.D. - Expanded Inside Diameter

The Expanded I.D. measures the minimum size of the Inside Diameter after the tubing has been expanded. Heat shrink tubing is sold in its EXPANDED I.D. size.

Lay Flat Width

The Lay Flat Width is the minimum width of the Expanded I.D. heat shrink in is flat form. This needs to be taken into consideration dependent upon its application.

The lay flat width is calculated by multiplying the External I.D. X 1.57

Recovered I.D. - Recovered Inside Diameter

When heat is applied to expanded tubing, the tubing will shrink or recover. The Recovered I.D. is the measurement of the Inside Diameter of the tubing after being allowed to FULLY SHRINK or RECOVER back to its original extruded size.

1. Determine the diameter size of the tubing.

Measure the diameter of the underlying materials to be covered - at the widest part.

Select tubing that is 20% - 30% larger than this measurement by referring to the product’s datasheet on the Website

2. Determine the shrink ratio of the tubing.

Heat shrinkable tubing is primarily available in 2:1or 3:1 shrink ratios meaning the tubing has been expanded to twice or three times its fully recovered size. The greater the size variations of the underlying materials being covered, the larger the shrink ratio required.

3. Determine the wall thickness of the tubing.

Nominal Recovered Wall Thickness - The target thickness of the wall after complete recovery. The Wall Thickness of the tubing is measured in inches (in.) or millimeters (mm). Refer to the tubing’s Technical Data to determine the thickness of the wall.

4. Determine the length of the tubing.

Longitudinal Shrinkage: Heat shrinkable tubing has a small loss of length during the recovery process. Take into account the change of length of the recovered tubing (after shrinking). Longitudinal shrinkage varies from 5% to approximately 10% - depending on the material.