UL 467 does not have a standard resistance test, but does have a continuty and current test requirement for standard-grade fittings and clamps.
In section 14.1 Table 14.1, and depending on the trade size of the fitting, the current shall be carried between 4 and 9 seconds at between 300A and 12,000A. After such test, a continuity test shall be done using an ohmmeter, buzzer/battery combo, or the like.
IF it is a hospital grade fitting, there is a contact resistance test. "30A through fitting. The resistance shall not exceed 0.030 ohms nor be more than 0.005 Ohms greater than the resistance of the grounding cord assembly measured from the tip of the plug to the terminal connector."
I hope that answers your question.
-Larry