Heat shrink tubing is used everywhere you use wire and cable to provide protection, identification, sealing, and strain relief, as an alternative to taping, molding, or potting. When heat shrink is heated, it will conform to the shape and size of the object that it has been shrunk over, making installation quick and easy. Learning the importance of high-ratio shrink tubing is essential to the completion of certain projects.
When using heat shrink tubing, you will need to consider the shrink ratio to ensure the heat shrink tubing will be able to cover the material you are trying to protect. The most common shrink ratios are 2:1, 3:1, and 4:1, but there are much higher shrink ratios available such as 6:1.
High-Ratio
A high-ratio means that the heat shrink tubing is more suitable for objects like connectors as it can encase the connector body and still be able to shrink down to a smaller diameter such as a wire or cable. In general, it is recommended that the supplied inner diameter of the heat shrink tubing and the size of the object to be protected should not exceed a 40% ratio to allow for effective coverage.
Choose Wisely
Choosing the right heat shrinkable tubing size is all about taking the right measurements. Use a caliper or a ruler to measure the diameters of the smallest and largest parts you will be covering with the tubing. Choose heat shrinkable tubing that is twenty to thirty percent larger than your largest measurement. The extra twenty to thirty percent will allow room to slide the expanded tubing over the largest part. Do not forget your small measurement, though. Check to make sure that the heat shrinkable tubing has a high enough shrink ratio to get a snug fit on the smallest part you wish to cover.
Common Heat Shrink Ratios
• 2:1 – This heat shrink tubing will become half of its original size once the heat is applied. The original heat shrinkable tubing is twice as large as its shrunken form.
• 3:1 – This heat shrink tubing will be one-third of its original size once the heat is applied. The original heat shrinkable tubing is three times larger than its shrunken form.
• 4:1 – This heat shrink tubing will be one-quarter of its original size once the heat is applied. The original heat shrinkable tubing is four times larger than its shrunken form.
If you have any questions or concerns regarding the correct usage of heat shrink ratios, don’t hesitate to contact Nu-Tech. We’re here for you.
