Current capacity depends on application and number of wires in one jacket.
Stepper motors by their nature never have maximum current in all conductors
at the same time. My personal practice is to use a value less than the "chassis
wiring" rating and more than the jacketed cable rating which assumes all
conductors carry the same current.
For 22 AWG jacketed cable feeding stepper motors I am happy with up to
5 amperes rated motor current.
For 20 AWG jacketed cable feeding stepper motors, I am happy with up to
7 amperes rated motor current.
For 18 AWG jacketed cable feeding stepper motors, I am happy with up to
10 amperes rated motor current.
Do pay attention to terminations. For wire in these sizes, even a few strands
missing in the crimp or clamp can significantly reduce current carrying ability.
