
Electrical tape is a crucial part of any electrician’s toolbox. It is used to cover and insulate a wide variety of electrical wires and cables as well as identify them by voltage level and phase.
Because electrical tape is used daily by those in the field, it plays an essential role in maintaining electrical safety. And just like with other safety products, you must know what you are looking for when selecting the proper electrical tape.
A key characteristic for selecting a high-quality tape is elongation. Elongation is the measure of how far the tape can stretch before it breaks. Knowing the elongation rating (measured in percentages) will tell you how well it can handle the continuous stress of being stretched, once it is applied.
When it comes to sealing out contamination and moisture in critical applications, a high-quality tape will offer you the elongation properties necessary. When you stretch the tape to apply it to the wires, it will naturally want to constrict back to its original state, forming a “living memory.” This is very important because the living memory is what keeps the tape tightly secured to the wire, blocking out the moisture and contamination.
Here are a couple of methods for testing elongation that you can perform with little effort at home or in the field:
- Take a piece of electrical tape, stretch it, and apply it around your finger as if you were wrapping a piece of wire. If you feel the tape immediately tightening, then that is a good indicator.
- Attach at least a 2-inch strip of tape to a table, hold the end attached to the table while stretching the other end outwards, to about double its length, and then let go. If the tape quickly retracts back to its original form, that is a good indicator.
StrongHold offers a comprehensive contractor offering, including high-quality electrical tape.
Interested in seeing how StrongHold Electrical Tape compares against the leading competitors, check out this elongation testing video.
In this video, you will witness the elongation properties and living memory capabilities, tested by a machine designed to apply equal pressure on all tapes and stretch them by 200%.

To learn more about our entire line of StrongHold products, click here.
Paying attention to the elongation of the tape is crucial for quality and safe wiring jobs! that can be a difference between amateurs and quality electricians and electrical contractors. We do a lot of home rewiring in Parker area, and sometimes we are surprised with really bad wiring due to poor quality tape applied. Thank you for your great article!
These are great tips. Tape’s ability to elongate definitely goes a long way. It’s a good way to test if it can friction. It will make sure that your efforts and
quality job is maintained.
Great article. I completely agree with all the points. Thanks a lot for sharing such a great piece of knowledge with us.
I appreciate for your efforts taken to write about why is elongation important in electrical tape. I agree with all the factors listed by you since these are very important factors to be taken into consideration prior deciding on anything. Thanks for the info!
Great article guys, what makes this article so great is the fact that you pretty much bring up why is elongation important in electrical tape. Keep up the good content, thank you for even taking the time to share.
Nice to read. You have clearly explain it very well.
Thanks for this very insightful article. Knowing the right way on how to safely use electrical tape is important. This is very helpful information specially for beginners.