Sizes and shrink ratio of heat shrink tubing | WKK

When choosing the right heat shrink tubing for your intended application, it is important to also choose the right size ánd shrink ratio. Read more about how you choose heat shrink tubing in the right size and shrink ratio in our blog.

Heat shrink tubing shrinks in two ways when heated: in length and in diameter. In length, heat shrink tubing shrinks 0% to a maximum of 10%. The extent to which heat shrink tubing shrinks in diameter depends on the shrink ratio. Heat shrink tubing with a shrink ratio of 2:1 has a diameter after shrinking that is 2x smaller than before shrinking. In other words, heat shrink tubing with a diameter of 10 millimeters before shrinking and a shrink ratio of 2:1 has a diameter of 5 millimeters after heating.

How far heat shrink tubing shrinks depends on the shrink ratio. This can be 1.5:1, 2:1, 2.5:1, 3:1, 4:1 or 6:1. The shrink ratio indicates to what extent heat shrink tubing shrinks in diameter after it is heated.

The heat shrink tubing size you need depends on the thickness of the cable on which you will use the heat shrink tubing. Always choose heat shrink tubing with a diameter after shrinking that is slightly smaller than the diameter of the cable. This way, you can be sure that the heat shrink tubing fits tightly around the cable after the heat shrink tubing has been shrunk.

For example: if you want to use heat shrink tubing on a cable with a diameter of 5 millimeters, choose heat shrink tubing with a diameter after shrinking of 4 millimeters.

The shrink ratio is calculated by looking at the diameter of heat shrink tubing before and after shrinking. How many times smaller the diameter of the heat shrink tubing is after heating compared to before heating is the shrink ratio.

For example, if heat shrink tubing has a diameter of 27 millimeters and is only 9 millimeters after heating, then the heat shrink tubing has become three times smaller in diameter. The heat shrink tubing therefore has a shrink ratio of 3:1.

Do you need help in choosing the right size and shrink ratio? Our advisors are happy to help - contact them directly.