What is most durable cord design


Flashlight Enthusiast
Oct 27, 2007
Akron, Ohio
My life is plagued with failing cord and ends. I must have spent $200 this year repairing extension cord ends. (Heavier gauge cords seem to fail faster than lighter gauge.) I must have went through 6 micro usb cords in last six months. I probably destroy on set of earbud cords every 3 to 5 weeks. Have sent away 3 times for Fenix HP 11 cord replacement. Have had 2 or 3 homemade headlamp cords short. Spent about $30 recently on cloth covered earbud cords. Some vinyl insulation seems to dry harden on its own in in a month after opening package and crack, breaking wire.

Yet, I don't remember, Ma Bell, having cord issues on Phone owned phones (prior to mid 1980s). The only thing I can imagine is high quality thin copper, in loops style cord with quality insulation.

Any Cord University on web? Any opinions?


Oct 7, 2003
Near Silicon Valley (too near)
I'm not an expert, but I can tell that you need relief, and you need it fast. Strain Relief, that is.

Cords break because of too much bending or pulling. The sharper the bend, the more stress there is on the strands at the apex of the curve. The built in stress relief on a set of earbuds is that silly tapered plastic thingy that the cord passes through at the plug. It's designed so that the curve there is gradual.

What a lot of us do is to wrap the cords tightly and bend the ends over as we tuck them in. That kills the cords fairly quick.

Back in the Ma Bell days the equipment was designed with a projected lifetime of 75 years. Yes. I said 75, and thats the number I remember from seminars when I worked there. Parts subject to early failure were duplicated so that the device would continue working. Part of the reason they were dismantled was that AT&T was accused of overbuilding equipment, thus spending more than it needed to. They were accused of money laundering because AT&T was buying that equipment from it's own subsidiary company.

You can extend the strain relief by adding a bit of heat shrink tubing to the existing strain relief. This will move the stress further down the cord. If the heat shrink is large enough, it will spread out the bending without moving the "pulling" support. This can spread the damage, causing it to last longer.

The same ideas apply to larger power cords. Strain relief can extend the life from years to decades. ( at which point the insulation breaks down an starts a fire instead. :) )


lucca brassi

Feb 1, 2008
Kocevje , Slovenia, Europe
If you have cord that is meant to be bend and twist , than you have to choose ''SUPERFINE Cu STRAND CABLE ''+ proper cable gland .

You have to look on cords like microphone cord for lower power and speaker cord for higher power ( normal cable or coaxial is OK (you would have only DC without some frequency )) .

First you would noticed is very fine coper wires inside and insulation shell is not from PVC or similar plastic but from silicone or silicon rubber based material.



In my diving lamp i use these

http://www.cordial.eu/en/products--find-your-cable.html for your purpose i would choose something like ''Microphone Cables CMFLEX 222'' it have otherwise higher diameter but it is high flexibility cord
Last edited: