As I understand it: The duty cycle is the amount of time you can spend with the unit 'on' and then 'off' - so you could spend 6 minutes on, and then have to wait 94 minutes off. Those are just random numbers based on 6%. The documentation will say the max continuous run time in addition to the duty cycle. 6% is pretty low. Professional welders pump only as much current as they can safely dissipate the heat so they can run 100% duty cycle. Something small like this would be good for doing a small weld here and there - hobby quality.