EVSE charger lock.. is the hole diameter 1/4 or 1/8"?

While the design of this connector may be an industry standard, the size of the hole for the lock apparently is not. You'll have to measure your own connector to know for sure. My 40-amp eMotorWerks JuiceBox with optional "soft" cord has a lock hole that is a tight fit with an 11/64" (.172") drill bit. Anything smaller will fit. I don't know what size the hole is in the car's supplied connector. I've only had that EVSE out of its storage bag once, to make sure that it works. It hasn't seen daylight in over a year.