The dual platinum and platinum/iridium OEM plugs that I work with are all nickel plated on the threads to prevent any sort of galvanic bonding that might occur in the plug threads. I haven't run across any problems with people removing the plugs even at very high miles when their curiosity gets the better of them. Not that plugs cannot "seize up" I guess...but that idea was, once again, one of the old wives tales created by plain, steel spark plug shells in plugs that were meant to be removed every 6K for a "tune up".