I'd check into one of those stainless steel weldless fittings and see if it has enough depth for the .20 TC cap. I've seen some thermowells with the weldless fitting but you might have to adapt a couple pieces to get what you want, like a separate thermowell that threads into a weldless fitting. Getting the thread depth is the key with the thickness on the TC cap. Besides Amazon there's several places that specialize home brewing fittings, valves and such.