RJ45 Cable Patch Cord Cat5e Lan Cable For Network Cable
There are two main physical differences between CAT5 and CAT6 cables, the number of twists per cm in the wire, and sheath thickness.
Cable twisting length is not standardised but typically there are 1.5-2 twists per cm in CAT5(e) and 2+ twists per cm in CAT6. Within a single cable, each colored pair will also have different twist lengths based on prime numbers so that no two twists ever align. The amount of twists per pair is usually unique for each cable manufacturer.