Yes, they can stretch a little over time and strain. But they can only stretch a little as they are metal which can only stretch so much. There are two basic components in a cable. You have the conduit (the outer housing/tube) and the strand (the part that goes into the tube).

Yes, steel cable (wire rope) undergoes two distinct types of stretching over its lifespan: constructional stretch and elastic stretch. Constructional stretch occurs early in the cable's life as the individual wires and strands "settle" into place and compress the core under load; this is a permanent elongation that usually amounts to about 0.5% to 1% of the total length. Once this initial settling is complete, the cable behaves elastically, meaning it will stretch temporarily when a weight is applied and return to its original length when the load is removed—provided the load stays within the "elastic limit." However, if a cable is consistently overloaded or subject to extreme wear, it can suffer from "creep" or permanent deformation where the steel fibers themselves begin to thin and lengthen. In applications like elevators or suspension bridges, this stretch is meticulously monitored. Engineers often "pre-stretch" cables during manufacturing to minimize constructional elongation after installation, ensuring that the cable maintains its structural precision and safety ratings throughout its service life.