On my bathtub the faucet stem screw that holds the handle on, is stripped. This cartridge stem does not appear to be easily available, in fact no one has been able to determine the manufacturer of the faucet and it is not labelled. The cartridge turns off the water just fine, but the handle keeps falling off. The hole in the handle is not big enough for a larger screw. I suppose I could drill it out, but I'd rather find another method to fix this, and besides I am afraid that a larger diameter screw might split the shaft. I dont want to glue the screw in there or I'd never be able to get the cartridge out if it needed work. I already tried to put a paper matchstick on the hole but that only lasted a short time. Then I tried aluminum foil but that only lasted a short time too. I am not willing to rip the bathroom wall apart to replace the entire faucet, not mentioning the expense. Is there an easy way to fix this so the handle will stay on?
Note: I said the cartridge and shaft are plastic, but they are a soft plastic, probably what I think is called nylon.
Thanks
Gerry