Flexibility and Flex Life: Understanding Your Wire and Cable Needs

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Flex Cable

May 26th, 2017 - Given how many cable systems are required to tolerate movement – whether small amounts during initial installation or repetitive daily motion – understanding the flex requirements of a given application is crucial to choosing the right wire and cable. When looking at cable types, terms like “flex,” “flexibility,” and “flex life” show up often. Within the world of “flex,” flexibility and flex life may sound equivalent, but there are key differences. In fact, some high flex cables can have short flex lives, and other wires and cables with high flex life may not be particularly flexible.


Simply put, flexibility is a measure of how much movement a cable can tolerate at a given time. Flexibility comes in many types; torsional, rolling, bending, and variable all describe different kinds of flexibility. When a cable is bent, twisted, or pulled into positions other than its original state, its flexibility is tested. Flexible cable can bend significantly and stay bent for a large amount of time without being damaged.

Will your cable need to be bent or curved around infrastructure? If so, you may need high flex cable, or cable with strong flexibility.

Flex Life

Flex life deals less with how the cable moves, and more with how often it can move in these ways without taking serious damage. Many cables can bend to some degree for limited use (e.g., installation). High flex life cable can bend repeatedly and regularly without disrupting the cable’s intended use, such as power supply or data transfer.

Will your cable be subject to repeated movement such as is needed in robotics? If so, you may need cable with a high flex life.

Ultimately, the distinction comes down to use and application. If your cable needs to move well, it must be flexible. If your cable needs to move often, it must have a high flex life. In many applications, such as industrial machinery or factory automation, both flexibility and high flex life are required.

Northwire tests extensively for both flex and flex life and offers a number of standard wire and cable and custom cable options to meet varying needs.